A metallurgical detective story

There are people on eBay selling "liquid metal bullion".

They don't like to tell you exactly what metal this alleged "bullion" is, except they always swear it doesn't have any mercury in it.

They generally say it's solid at room temperature, but will melt from the heat of your hands.

Those of us with a mild recreational interest in the periodic table will draw a rapid conclusion if given the characteristics "metal, melts at body-heat temperatures, doesn't explode on contact with moisture...

...and non-toxic."

That'd have to be gallium, right?

Wrong. I bought some, and it's nothing like the gallium I already own.

I didn't know what the hell the "liquid bullion" was. Not, at least, until I played around with it for a while.

Fusible metal ingot

There seems to be some sort of tradition in the hobbyist low-melting-point-alloy business of casting your little ingots in unorthodox moulds. The mould is usually something that clearly indicates that the metal was liquid at temperatures low enough that to not instantly destroy a chocolate-box tray, silicone ice-cube tray, or similarly non-refractory mould material.

Wood's metal casting

I cast my own Wood's metal in a Lego mould.

You could craftily fake this by casting wax in a chocolate tray, then using that form to make a sand mould, or something, but I don't know of any such scandals in the retail weird-metal market.

All of the low-melting-point alloys exist because of the odd fact that mixtures of chemicals can have a lower melting point than any of the ingredients.

On the face of it, this doesn't make sense. I mean, the universe should be nice and sensible and line up with the way ancient philosophers hoped it worked, from tiny billiard-ball atoms all the way up to clockwork galaxies. Then, the melting point of an alloy would be the melting point of its constituents, weighted by what proportion of the alloy each constituent took up. So for Wood's metal, for instance, you'd have:

50% bismuth, melting point 271.5°C
26.7% lead, melting point 327.46°C
13.3% tin, melting point 231.93°C
10% cadmium, melting point 321.07°C

Weighting each of those by the fraction they take up gives 135.8, 87.4, 30.8 and 32.1; add those up to get your naïve simple mathematical logical melting point and you get 286.1°C.

The melting point of Wood's metal is actually only about 70°C. Stuff like this is why metallurgy was much more art than science for a long, long time.

(In case you're wondering, which you probably aren't but I was, for these kinds of calculations it's safe to use Fahrenheit, Celsius or Kelvin temperature scales. The arbitrary zero points of Fahrenheit and Celsius don't screw it up. Beware anybody who tries to tell you that a 30°C day is "twice as hot" as a 15°C day, though, because that's so dumb as to possibly be not even wrong. 15°C is 59°F, for instance; making 59°F "twice as hot" gives you 118°F, which is 47.8°C. Kelvin starts at absolute zero, so it's the only scale in which you could actually fairly say one temperature is twice another, though I'm still not sure how useful such an observation could be. Starting at -273.15°C makes "doubling" room temperature in Kelvin rather dramatic, though; 15°C is 288.15 Kelvin, double that is 576.3 K, which is 302.85°C.)

Many alloys don't have this oddly low melting point. Brass, for instance, has a melting point from about 900 to about 940°C depending on its formulation; it's composed of copper (melting point 1085°C) and zinc (melting point 420°C). The melting point of brass is higher than you'd expect from naïve proportion calculations.

But the most common low-melting-point alloy is ordinary tin-lead solder, which exhibits the melting-point-reduction effect. Tin melts at 232°C, lead melts at 327°C, but if you mix 63% tin with 37% lead you get an alloy that melts at only 183°C.

And so, back to my "liquid bullion" ingot, which I bought on eBay Australia for $AU19.01 delivered after watching several people buy their own for prices that exceeded my modest snipe.

It was quite small. Only about four centimetres in length...

Fusible metal ingot in hand

...and it weighed more than fifty grams.

That made it dense enough that, despite the seller's claims of non-toxicity, I treated it as if it were made of solid cadmium until I could figure out the thing's composition for myself.

(The seller was this guy - possibly NSFW! - who is now out of the "liquid bullion" business, having found the whole thing to be "nothing but a headache". That "NSFW" is there because after he got out of the liquid bullion business, he sold several pornographic coins. I am not making this up. As I write this he's only selling a sofa, but I'm sure he'll offer the Internet flea market some more eyebrow-raising products in the near future.)

The listing for my "bullion" ingot gave no hints regarding its makeup, but I bought it anyway, partly because low-melting-point metals interest me. I also figured that "liquid metal bullion" might be just as entertaining as "copper bullion", with which I had a lot of fun a few years ago.

(Tl;dr: Base metals sold by the troy ounce may be a fun novelty, but are not a good investment.)

Copper-bullion sellers are still rampant on eBay, but this liquid-metal schtick is new, and extraordinary.

It is, you see, mystery bullion! An unknown metal! Usually billed as very rare and valuable and desirable, whatever it is, but available to you today for amazing prices!!1!

I saved the listing from which I bought my little ingot. I won't upload the whole page-copy here, though, because malware-detection services tend to flip out, with some justification, if they find what looks like an eBay listing on some site other than eBay.

Here's what the listing said, though, with only the eBay trimmings and images removed.

Children, avert your eyes! Just reading this may delete more than a year of science education from your brain, and make you noticeably less intelligent than you were before!

999 Pure Liquid Metal Bullion INGOT 99c A GRAM 52.6 Gram Not 1oz Silver bar Coin



You will receive 1 ONE
Ingot as pictured which weighs 52.6 GRAMS IN TOTAL. Size is (1 & 3/4" long) (1" Wide)  (1/4" High)





Purchase as many as
you like. You will only pay the quoted postage cost as I will cover any EXTRA

This metal is
considered  bullion as it is pure rare

It melts at the low
temperature of less than 30 degrees, will even melt in your hand if held long


Spot Price is
increasing at a rapid rate with the demand of this

Pure Liquid Metal

Only 99 cents per
gram and one off low postage cost of $3.00

There's... I mean...

Look, I'm not even going to start with that description. It's the sort of scientific word-salad more often seen in explanations of crackpot cancer cures.

Oh, OK, just one thing: "Rare earths", and metals which are precious for their rarity, are not the same thing, no matter what certain eBay sellers think.

The elements known as "rare earths are actually quite common; the only "rare" thing about them is their concentration in any given load of ore, meaning you need to dig up a lot of the planet to get a little bit of rare-earth element. And then it's difficult to separate the different rare earths from each other, because several of them have very similar chemical properties.

Rare-earth elements are today used to make neodymium-iron-boron magnets, hence the term "rare-earth magnet". Modern lighter "flints" are made from a very sparky, pyrophoric...

...and somewhat excitable...

...alloy of different rare earths, plus a few other things and iron for strength.

Rare-earth magnets and lighter flints are not very expensive per gram, though, because they contain no precious metals. For a few bucks you can now buy a ferrocerium stick intended for use as an emergency fire-lighter - just scrape it with a knife blade, file or similar item to create a shower of sparks.

(There are fancy versions of these things with built-in scrapers, but a simple bare ferrocerium rod is almost as good. You can get a little one with a handle, perhaps a stick of magnesium too for use as high-temperature tinder, and a bit of hacksaw blade for scraping and spark-striking, for about a dollar delivered. A chunkier bare ferrocerium rod will only set you back a few bucks from a dealer who doesn't quite know the difference between magnesium and ferrocerium, and may theoretically save your life one day. It will definitely provide you with considerable entertainment and some tiny holes burned in whatever happens to be near you when you play with it.)

The YouTube link in the above exercise in eBay creative writing goes to this video, from the brain-polluting "HouseholdHacker". That dude used to make ridiculous practical-joke "how-to" videos, which on the one hand encouraged a lot of adults to do entertainingly silly things, but on the other hand probably turned some kids off science. Which took that guy right the hell off my Christmas-card list.

Now, though, HouseholdHacker seems to be producing serious videos. The one linked to by the liquid-bullion guy isn't what you'd call packed with educational information, but the only actual inaccuracy I noted in it was incorrect rounding so the melting point of gallium was 0.1°F off. That is not exactly a capital crime.

But I still think that you're going to transition from "joke videos to get people to do stupid things" to "actually telling the truth", you shouldn't keep your old name. Mixing the two is completely uncool, man.

(Oh, and while I'm on this subject, see also my favourite example of this latter crime. Good ol' Kip deleted all of his highly remunerative Metacafe videos at some point after he reinvented himself as the video face of Make magazine, thereby ensuring that I stopped watching any of their videos. I think Make came to their senses and quietly fired him after a year or three; their videos are much better now, and they've recently started an interesting new series.)

If you want a video about low-melting-point alloys that's not from a professional bullshit artist, you could do a lot worse than turn to "Brainiac75":

Oh, and if you want a good video about gallium alone, then you obviously need to turn to actual scientists...

...and their magnificent example of an actual scientist who looks like a mad one from a horror movie.

Aaaaanyway, anybody who hasn't yet died of old age reading this page may remember that the question was... what is this "liquid bullion" stuff?

While I was sniping auctions, little fifty-gram ingots like mine kept selling for twenty-five Australian dollars or more. That's a good price for fifty grams of gallium, but it's not a good one for a similar amount of toxic low-melting-point alloy. Small amounts of anything cost more per gram, but you don't have to buy a huge amount to pay a lot less. Brainiac75 above said he paid only ten Euro cents per gram for some of the lower-melting-point alloys in his videos.

(The very lowest-melting-point alloys in Brainiac75's video are alarming concoctions like an amalgam of periodic-table neighbours mercury and thallium. That is not ten cents per gram, but it stays liquid down to -60°C. Cesium-potassium-sodium makes it down to -78°C without solidifying, but it also explodes on contact with water.)

For my first attempt at identifying the metal, I contacted the seller thusly, batting my eyelids innocently:

I've received my little ingot, and now I find myself wondering what it's actually made of. Your listing doesn't mention this, other than to say that it contains no mercury. What actually IS this alloy?

I'd also be interested to learn where to look up the "spot price" you mention in the listing. (Which again, of course, requires me to know what alloy this actually is.)


While I waited for him to reply, I measured the little ingot's density.

Accurately calculating the density of a small object is tricky. Getting a vague ballpark figure isn't hard, especially if the object is roughly a rectangular prism, as this one was. Just measure the edges, fudge any bevelled edges into a sensible-looking in-between number, and then multiply the numbers. Doing that with the little ingot gave me a volume of about 5.6 cubic centimetres. Since it was bang on its advertised mass of 52.6 grams, this gave me a density of about 9.4 grams per cubic centimetres.

The density of solid gallium is only 5.91 grams per cc, so clearly this wasn't gallium.

(Gallium is also one of those odd materials that expands when it freezes; liquid gallium's density at its melting point of 29.8°C is about 6.1 grams per cc.)

My faithful triple-beam laboratory balance gives me quite accurate weight numbers, but I wanted a more accurate volume than fudged dimension-multiplication could offer.

When a metal has a low melting point you can, of course, just melt it and pour it into a graduated cylinder to measure its volume. But gallium, if there was any of it in this alloy, tends to "wet" a wide variety of other substances. So, presuming there was gallium or something that behaves like it in this alloy, getting all of it out of a narrow graduated cylinder again could be difficult.

Another way to measure volume is by filling a graduated container with water or oil or whatever else is compatible with the object whose volume you want to measure, and then dropping the object into it and seeing how far the water level rises. This often doesn't work any better than just measuring the edges, though. It's a good quick strategy for extremely irregular objects - figuring out this technique is what is suppose to have sent Archimedes running naked down the street shouting "Eureka!" - but I've tried it several times with different items, and every time I got miserably inaccurate results.

There's a much better way of measuring object volume by immersion, though. You just need to add a precision scale to your apparatus. Pretty-well-calibrated 0.1-gram-resolution digital scales are now commodity items, and my abovementioned lab balance will do the job nicely.

What you do is, you put some water - or, again, a different liquid if water is incompatible with the object you're measuring - in a vessel deep and wide enough to completely submerge the item whose volume you're measuring, without the object having to touch the bottom.

You then weigh the vessel and the water, or just press the zero-out "tare" button on your digital scale.

Now, you immerse the item you want to measure in the water. If it's less dense than water you have to push it down into the water until it's fully submerged, but it's probably more dense than water, in which case you can just suspend it rather than push it in.

The important part is that the object must be immersed, but not resting on the bottom of the container. This is because what you're measuring is the increase in weight of the container, not the rise in level of the liquid in it.

Whatever you suspend your object with should have as close to zero volume as you can manage. I used some kapton tape, partly because it is narrow and extremely thin yet has good adhesive, but mainly because it is unquestionably the scienciest of all of the more than two dozen kinds of tape I have to hand.

("Florists' crepe-paper tape?" Got that. "Colourful metallic tape less than a millimetre wide meant for decorating fingernails?" Yup. "Copper and aluminium foil tape?" Of course. "Self-amalgamating?" Which kind would you like, the old rubbery type or the new silicone stuff? "Gaff?" Multiple colours. "Foam draught-excluding door-seal tape?" Please. "Bendable-fridge-magnet tape?" Yes sir. PTFE thread-sealing tape? Naturally. "Unstretchable fibre-reinforced tape?" Ashamed to say I have only glass-reinforced, must get the aramid kind too. "Velcro tape and liquid tape?" Possibly the first and definitely the second doesn't really qualify as tape, but I've got 'em both anyway. And you can buy off-brand probably-kapton polyimide tape all over the place these days; it's generally just called "high temperature tape".)

Again, if you're measuring the volume of a ping-pong ball or something by the immersion method then you'll have to push it down into the water, but that'll still work. You could push it in with three needles mounted on some gantry over the scale, for instance.

Anyway, you suspend or shove the thing you're measuring into the water, suspending or shoving as little other stuff in there as possible, and the vessel will then become heavier by the mass of the liquid the object has displaced. Water weighs one gram per cubic centimetre at one gravity, so presuming you're using water and don't need numerous decimal points of accuracy, each gram of weight gained equals one cubic centimetre of object volume.

If you're now having some kind of "common sense" brain-spasm, wondering why a ping-pong ball shoved into a glass of water should make that glass as much heavier as would an identically-sized sphere of tungsten suspended in it, you may find this PDF soothing.

The initial mass of my glass plus water was 436 grams even; dangling the "bullion" ingot in it raised that to 441.5 grams, for a volume of 5.5 cubic centimetres.

This made me pleased about my original guesstimate of 5.6 cubic centimetres, though slightly less pleased about the time I'd spent bent over a laboratory scale to get a scarcely-different number. It's a bit like that story about how the Great Trigonometric Survey painstakingly measured the height of Mount Everest and came up with exactly 29,000 feet. That's exactly how tall everybody had always said the mountain was anyway, so, the story goes, they added another two feet to prevent people thinking they'd actually just gone to ground in a club in Calcutta and spent their time inventing snooker and the gin and tonic.

Anyway, 5.5 cubic centimetres and 52.6 grams gave me a density of 9.56 grams per cubic centimetre.

I now had a reply from the seller regarding what he reckoned I'd actually bought. He said:

Hi, the metal is frenchs metal type3 or gallium, both the same.


He was receptive to my then pointing out that "French's metal" and gallium are very much not the same, the latter being non-toxic and the former containing both lead and cadmium. It was at this point that he told me he wasn't selling this stuff any more on account of its headacheyness, which is I suppose one way of describing what happens when you sell poisonous heavy metals, both lead and rather more scary cadmium, as "non toxic and non hazardous to handle".

"French's metal" is an unusual term for an unpopular substance. It's easy to find people selling Wood's metal, which is bismuth, lead, tin and cadmium, and melts around 70°C. Rose's metal is also pretty commonplace; it's just bismuth, lead and tin, so not as poisonous as Wood's metal, and melts just below the boiling point of water.

French's metal winds the melting point down to only about 41.5°C by adding indium to the Wood's-metal mix. There are some further variants that melt even lower thanks to the presence of thallium as well; if this stuff really melted in your hand, I strongly suspect it'd have to be one of the thallium alloys.

Which would be bad. Especially if you were melting it in your hand.

There are very good reasons to have as little thallium in your life as possible. Cadmium is something in the order of ten times as toxic as lead, but you can at least touch the stuff with your bare hands without appreciable danger, provided you wash your hands thoroughly afterwards.

Metallic thallium can pass through the skin, though, and is much more toxic than cadmium. Exact comparisons are difficult, because human thallium exposure is usually via one of its several useful-yet-toxic compounds, rather than the pure metal. But thallium is probably tens, if not hundreds, of times as toxic as cadmium. See this PDF from the US EPA, for instance, and compare with MSDSes (previously) for cadmium, like this one or this PDF one.

You really, really don't want to get any thallium on you.

(One of the symptoms of thallium poisoning is that your hair falls out. Needless to say, this means thallium sulfate used to be used as a depilatory, not that long ago. See also the use of lead and mercury compounds for skin whitening. Thallium is also still used in some countries to poison rats, ants and troublesome spouses.)

Fortunately, most people don't need a fusible alloy that melts at as low a temperature as bismuth-lead-tin-cadmium-indium, and fewer people still need the alloys with thallium as well. Presumably, because of this relative unpopularity, "French's metal" and its relatives are often not called that, and just stuck on page 137 of the specialist-alloys catalogue with no name beside their ingredients and melting point.

On with the investigation, then. What actually is the melting point of this stuff?

If it were pure gallium then it would indeed melt in your hand, provided the ambient temperature was high enough; gallium melts at 30°C (86°F). It's too dense to be pure gallium, though, so if it melts at blood temperature then it's probably terrifyingly toxic.

"French's metal" formulations - without thallium - are frequently quoted as melting at 117°F, which is 47.2°C, way higher than any survivable body temperature. Similar alloys with added thallium are quoted as low as 105°F, which is 40.6°C and still not "body temperature" unless you're quite gravely ill. Measuring the melting point can therefore help me decide whether it's moderately-nasty French's metal or some handle-with-gloves thallium alloy.

I've got a high-accuracy digital probe thermometer, from back in the day when I reviewed incredible quantities of CPU coolers. (It's tempting to simplify the setup by just pointing one of today's inexpensive non-contact infra-red thermometers at whatever you're heating, but in this case that wouldn't work.)

So I set up the sort of advanced experimental apparatus for which I am so justly renowned...

Gimcrack apparatus for measuring melting point of fusible metal alloy

...with the metal ingot again suspended in water, but this time inside a resealable storage bag, of the type generically referred to as, but in this case not actually a, Ziploc.

The bag insulated the metal from the water, of course, and my temperature probe was in the water, not inside the bag to get all probably-cadmium-ed up. So I needed to be a bit crafty to get a useful melting-point number.

What we're interested here is how low the temperature the metal melts at is, not how high it is, if you get my meaning. So I ran the water temperature up to 50°C (122°F), at first. Then I turned the heat off and snapped the above picture of the setup, while the metal got around to melting.

Melted fusible metal in plastic bag

After taking this photo, I hung the melted metal in its bag back in the water, and allowed the water to cool.

As the water temperature fell through the low forties Celsius, the metal started solidifying again. Crystals started forming in the liquid, so at first the metal in the bag felt like a dense liquid with a little sand in it, then more and more like unusually heavy wet sand, until finally it solidified entirely.

I think this might mean this alloy is non-eutectic, with no clear melting point because different components melt at different temperatures. It could also just be the normal way a cooling metal will crystallise if you keep poking at it and examining its texture, though - the "liquidus temperature" is defined as the temperature at which solid crystals can coexist with melted material. I'm not sure.

The metal was wholly solid again when the water temperature was 40°C (104°F). Taking the bag's insulation effect into account, that told me the melting point was above 40°C and below 50°C, so the "melts in your hand" claim was clearly disproven, but I didn't yet have much idea exactly which alloy I was looking at.

I then ran the temperature slowly back up again, and the metal was re-melting, with the same sandy-liquid feel, by the time the water was back up to 47°C. But, notably, not when the water was only at 42 or 43°C, which would indicate a scary thallium alloy.

And then a pinhole opened in the corner of the bag and tiny droplets started escaping, and I terminated the experiment before I got heavy metals all over the kitchen again.

(Perhaps a genuine Ziploc® Brand bag would have been tougher. Squishing a gritty liquid with 83% the density of lead around in a the pointy corner of a polyethylene plastic intended to contain only food would probably cause any such bag to spring a leak, though.)

I could have re-bagged the metal and kept refining my temperature range, but what I'd done so far makes me confident that the melting point is somewhere in the 42-to-47-degree-C range, and probably the upper portion of that range. So I'm about 95% sure that this is indeed some kind of French's metal alloy containing lead and cadmium, but not deadly thallium.


If you want a relatively inexpensive fusible alloy to play with, go for Field's metal. It melts at about 62°C (144°F), and it contains only bismuth, indium and tin, so genuinely is non-toxic. Bismuth and indium are a bit expensive, which means Field's metal is too, but you could cast a teething ring out of it and probably not harm the baby.

Describing any of these low-melting-point fusible alloys as "bullion", though, is if anything even sillier than doing the same for copper. They're not worth enough per kilo to be an investment item, and most of them contain lead, cadmium and/or even thallium, which makes them less "valuable heirloom" and more "toxic waste".

Two low-melting-point metals, one assistive cat

Here, along with one helpful wubble, is where my own "liquid bullion" ended up. I've left it in the triangular shape the corner of the plastic bag gave it, along with the little spherical droplets that escaped into the saucepan. It's quite pretty, covered with tiny sparkling crystal surfaces; cooling it slower might have made bigger crystals, though nothing that could compete with bismuth.

To the right of the "bullion" lump is my sample of gallium, which is currently solid. Gallium is one of those substances that'll stay liquid below its freezing point if nothing serves as a nucleation point to start it crystallising. (The same thing can happen with water and various beverages in smooth plastic or glass containers).

Gallium sticks to almost everything, though, so if you slosh it around in the bottom of a container it'll make a silvery mirror out of whatever parts of the container-sides it touches. Once it finally decides to solidify - which, for my gallium at least, can take weeks - you can flick the flexible sides of the container to break the thin gallium coating off them. The result is what you see in the above picture - uneven coverage of the sides with thin plating I didn't manage to dislodge, and random dislodged flakes of gallium sitting on top of the solid layer in the bottom of the container.

(I rather like these little PET bottles, by the way. My gallium came from the Amazon seller in a tough grey translucent container that doesn't show it off nearly as well as this new one. Five of these eighty-millilitre containers, about 8cm high and 4.5cm wide, only cost me $AU3.88 delivered on eBay. They seem to be a couple of bucks more expensive now. UPDATE: But because they're standard PET bottles blown to shape from a preform, they shrink if you put them in boiling water! I think I can re-liquefy my gallium in one of these bottles, but now I've got one funny-looking one from pouring too-hot water on it.)

As I write this, the spot price of silver is less than $US20 per troy ounce; precious metals in general have taken a dive in the last few months. The spot price for gallium is at the moment maybe $US500 per kilogram, and one kilogram is 32.15 troy ounces. So gallium is something like $US15.55 per troy ounce, right up there with silver.

There is, just as with copper, no real liquid market (pun not intended) for small quantities of high-purity gallium. But the value of the stuff is sufficient that if you manage to buy it by the kilo at close to the bulk spot price, it really could qualify as an investment.

If you buy fifty grams of gallium in a little bottle from that Amazon dealer then you'll be paying a large markup on the bulk price, as is normal for metals other than the generally-accepted "precious" ones sold at retail in ounce quantities. It's also possible to quickly turn gold, silver or platinum into cash, if you suddenly need to. In a similar situation with gallium you'd have a hard time finding people who even know what it is, much less people who'll buy it from you at a fair price, in a hurry.

On the other hand, gallium's value is closely pegged to its real usefulness in the world. Gold, silver, platinum and palladium all have real-world uses, but their value is far higher than those uses justify. A large slice of the precious-metals market is people buying the stuff as an investment or just a store of value, perhaps as an alternative to a savings account in their shaky local currency. (India, in particular, has a strong tradition of storing household money in gold.)

Precious metals have never been a good long-term investment in the modern world, but they're portable and fungible, and that counts for a lot, even if you accept that you could make more money with index funds, bonds, or often even crappy-yield savings accounts.

Nobody's casting gallium ingots and keeping them in Fort Knox, though. Which is just as well, because the stuff would totally pull a Cryptonomicon if you turned the heating up too far.

A bottle of sloshy liquid non-toxic gallium is a lot more fun than a similar amount of similarly-valuable but much-easier-to-sell silver, though. I think that's a fair trade.

But don't buy weird "bullion" of any kind from eBay dealers, especially ones that say their product is non-toxic but aren't actually sure what it is. And if you are an eBay dealer selling weird "bullion", for pity's sake figure out what it is that you're selling, lest you be the next schmuck to put a "safe for kiddies!" sticker on a lump of cadmium. Or worse.

Small ridiculous object du jour

Crank-operated fan

This is a fan.

I am delighted to say it is every bit as demented as I had hoped it would be when I slapped down $US3.40 at DealExtreme to buy it.

(There's a green one as well, but that costs three dollars and sixty cents. What am I, made out of money?)

It is not a big fan. The diameter of the see-through rubbery blades when they're spinning is about seven centimetres (2.75 inches). The blades fold back at rest, and can thus get in the way of the crank a bit on start-up.

Crank-operated fan

The blades spin fast, though; they're heavily geared-up, and turn something in the order of 110 times per crank of the handle.

I think this fan may actually have a substantial calories-expended-to-air-moved advantage over a simple paper fan. Both cool your face while they warm up your arm muscles, but I think the crank-fan requires less effort.

It also takes up less room, both in your bag and when you're using it.

I wouldn't expect this plasticky little thing to last a whole summer of frequent use, though. But it's probably more durable than similarly tiny fans that run off batteries or USB power; no motor brushes to wear out or solder joints to let go.

I think the principal purpose of this device is to make other people smile when you use it, though, and on that count it seems entirely successful.

And yes, you can turn it to point away from you and crank the handle the other way, and run about pretending you're an aeroplane.

EDIT: I just opened it up.

Crank-fan gears

Black plastic gears on metal shafts, and a couple of actual bushings for the output shaft. The bushings are only plastic too, but should wear slower than if there were only holes in the casing plastic for the fan-shaft to go through. This trinket was not just thrown together.

(The gears were dry; I added some fancy plastic-safe oil, and now I think the fan turns more quietly. This may be a complete fantasy.)

Even if it breaks after a month, it's difficult to complain when the thing costs very little, including delivery, for this orange one, and very little plus twenty cents, including delivery, in green.

(DealExtreme have bulk-buy discounts as well; you pay an extra $US1.70 for the whole order to use the "Bulk Rate" feature, then pay less for three or more of any given item in that order. The three-unit prices for these fans are only two cents more than the ten-unit prices.)


A crafty religious ambush

The other day a reader contacted me (I'll identify him if he asks me to). He'd read my piece about collecting old technology, and in lieu of a donation sent me a Diamond Mako for free.

How cool is that?!

Diamond Mako PDA

The Mako is a Psion Revo with different stickers on it. So it's a fold-open PDA, marginally bigger than a really humongous modern smartphone. It dates from those peculiar few years when having a phone-book on a digital device that couldn't make phone calls was normal.

The Mako/Revo is about the cutest thing ever to be decorated with a QWERTY keyboard. The battery in this one is pretty clapped-out, though; I'll need to replace it if I don't want to charge the thing, via this well-thought-out setup...

Variac step-down electrical mishap waiting to happen

...pretty much daily.

Along with this PDA-I-might-take-notes-on-one-day-if-I-can-get-it-to-IrDA-to-a-modern-computer, though, also came that most earnestly offered and least frequently appreciated of gifts...

Religious tract cover

...a religious tract!

Fair enough.

New rule: I'm perfectly happy for anybody to proselytise at me, as long as their religious literature is accompanied by an interesting piece of superannuated technology.

I haven't quite worked out my full schedule of fees yet, but an Amiga 600 that can run Speedball II from a CompactFlash-card "hard drive" will earn you complete perusal of a volume of religious literature not exceeding 100 pages. Give me a working NeXT cube and I will attend any service, no matter how long, at any church you specify within 150 kilometres of my home.

This tract is pretty standard stuff, but my correspondent asked me to read it and tell him what I thought, so that's what I'm going to do, in my usual buys-ink-by-the-tanker-load style.

I can't imagine that I'll be telling him, or any of you, anything you've not heard or thought before. But the fact that he sent me this thing, presumably in the expectation that it might cause the scales to fall from my eyes and the majesty of Jehovah to sweep me away, bothers me more, the more I think about it.

Just saying why this tract, to spoil the ending, does not persuade me at all, may be worthwhile.

(I did Google and Tineye image searches on the rather gaudy cover picture, to see if this particular tract is online anywhere else; I didn't get any matches, though Google's "Visually similar images" are pretty darn spectacular, and probably include Captain Goodvibes somewhere. Searching for a chunk of the text of the tract, which I'll include in this post for the convenience of future searchers, turned up one hit, at "Evangelical Tract Distributors". They have this tract with a boring non-psychedelic cover, "on sale" for zero dollars and zero cents. They'll send me in Australia up to a thousand similarly free tracts for only a $US20 shipping fee. It's twenty bucks for one tract too, though.)

Side one of religious tract

Side 2 of religious tract

Mercifully, this tract has only four small pages, making the old-technology-gift to religious-enthusiasm ratio pretty darn favourable, if you ask me.

Legibly larger versions of pages one through four are here: One. Two. Three. Four. And here's the text:

SEARCHING, probing, questioning, people are always looking for answers. From the vastness of outer space to the tiny world of microcircuits, all questions demand answers. But there is one question, life's greatest question, that many avoid. This question darkens the brow and fixes the gaze on eternity for it asks, "Where will I go when I leave this world?"

As people get older they often try to escape this question. Nonetheless, the question remains and all must face it [all underlining my correspondent's, not the tract's]. Perhaps you are avoiding it because you are not sure if there is an answer.

There Is an Answer

God has assured us in His Word that we may know the answer. Here is God's statement about it: "He that hath the Son hath life; and he that hath not the Son of God hath not life. These things have I written unto you that believe on the name of the Son of God; that ye may KNOW that ye have eternal life" (I John 5:12-13).

So we see that we may know where we are headed after this life and that there are only two possible choices. We may know if we are safe in Christ having eternal life and on our way to heaven, or if we have rejected Christ and are on the way to the terrible place awaiting all those who despise God's offer of salvation.

He that "hath the Son" hath life, eternal life. He that hath not the Son of God as his Savior hath NOT life. It is not a question of how good a life you have lived. It is a question of God's Son. Do you have Him as your personal Savior? Can you truly say that you know Him, that you have come to Him, that you have placed your faith in Him? "Acquaint now thyself with Him. and be at peace" (Job 22:21).

In Which Class Are You?

"For the preaching of the cross is to them that perish foolishness; but unto us who are saved it is the power of God (I Corinthians 1:18). So again you can see, God's Word describes some people as "them that perish," and others as those "who are saved." In which class are you?

Perhaps you are living a good. respectable life, and you feel that you are good enough already, and do not need a Savior. Or perhaps you are in the opposite class, and feel that you are too bad to be saved. God's answer in either case is plain: "...There is none righteous, no, not one" and "...there is no difference: for all have sinned, and come short of the glory of God" (Romans 3:10, 22, 23). We are all sinners. God's Word says that we are all "dead in trespasses and sins." We all need a Savior.

"But God commendeth His love toward us, in that, while we were yet sinners, Christ died for us" (Romans 5:8).

And God's invitation of mercy and salvation goes out to all alike. For He so loved the world that He gave His only begotten Son, the Lord Jesus Christ, that WHOSOEVER believeth in Him should not perish but have everlasting life (John 3:16). We beseech you to receive Him into your heart as your Savior. For "as many as received Him, to them gave He power to become the sons of God" (John 1:12).

It Is Up To You [handwritten: "Daniel Rutter!"]

You, yourself must decide the answer to Life's Greatest Question, "Where will I spend eternity?" It all depends on what you do about God's Son. For, "He that believeth on Him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God" (John 3:18).

Answer the great question today; believe on the Lord Jesus Christ and KNOW that when you leave this old world that you will spend eternity in the presence of your great God and Savior, Jesus Christ.

152 W. Prairie Ave.
Coeur d' Alene, ID 83815

[This would appear to be that church.]

Oh, boy.

Here's what this tract says, boiled down:

"If you accept the Christian belief system, why don't you accept the Christian belief system?"

That's it. That's all it's got. It says that you have to be a Christian to go to heaven and avoid hell, and it says that again, and then it says it a couple more times.

And, in the immortal tradition of all religious certainty, this tract cheerfully ignores the fact that several of its claims aren't even agreed upon by all Christians.

There are plenty of Christians who don't believe hell exists, for instance. This is not surprising, since it is exceedingly difficult to imagine why a loving god would visit hideous screaming flaming-sulfur acid-burning fingernail-peeling eye-gouging lye-drinking tooth-ripping knee-smashing genital-mincing torture for a trillion trillion trillion trillion trillion trillion et cetera years on Adolf Hitler, much less people who just thought religion was a load of claptrap and lived a good life.

(This tract actually has a bit of a bet each way there, because it doesn't actually mention hell, or lakes of fire or eternal torment - it just talks about a "terrible place" or where one might "spend eternity". This is compatible with the idea of eternal death being the only non-heaven option, rather than eternal punishment.)

There are also plenty of Christians who believe heaven, if it exists, is where good people go, whether or not they've kept any particular day holy or prayed on any particular schedule while pointed in any particular direction. Again, it's difficult to figure out why a loving god made us with this demonstrable inability to determine which, if any, of our thousands and thousands of contradictory religions, is the one true path to paradise. But this tract says he did, and we'd better choose right, or else.

And then there's the odd modern invention of the concept of a "personal relationship with god". This, also, is very far from universally accepted, even among Christians.

If you've got a personal relationship with someone they probably at least occasionally say things to you, after all.

It can also be argued that the very notion of a human having a personal relationship with the infinite creator of the universe is far, far more ridiculous than the notion of an E. coli bacterium having a personal relationship with the human whose gut it inhabits.

Now, this is all just part of the miraculousness of the Lord, of course. He's someone you can have a chat with, even if he doesn't seem to say anything back in a way that can't be blocked by appropriate medication. And he's simultaneously someone who sees the totality of reality spread out before him like a vast polydimensional tapestry, yet you also have free will, unless you're a member of one of the religions that says your eternal destination is known to God before you are born.

And so on, and so on, and so on.

If your religion were true, then just showing someone a tautological tract like this one would be likely to convert them in a flash of spiritual magic. You should be just dripping with miracles, like all of those people in the Bible. Some or all of the true believers should, to give one way in which a true religion might manifest itself, be able to speak in tongues - which is to say, your words should be comprehensible to everyone who hears them, no matter what language the astonished listeners speak.

Instead, religious people who "speak in tongues" have decided that it's actually just babbling away nonsensically in ways usually linquistically connected to languages of which the speaker has experience. It's often alleged that this is the language of angels, and it can be understood by some other members of the congregation, who stand up dramatically to "interpret" the doodly boodly boo boo boobly. (Or maybe it's a "private prayer language", whatever that means.)

I presume you're not a glossolalist, though. You probably have some sort of cessationist explanation for why the sun no longer stops in the sky and bushes no longer spontaneously combust and then start talking. You probably think people who do believe in ongoing but silly-looking modern miracles of one kind or another are misled. Perhaps to the point where the ones who say they're Christians are in fact not true Christians at all, any more.

But how can you tell?

What is it that suggests to you that the mainstream Christian ideas in this tract are the correct ones?

The tract, once again, presents no argument.

One wonders why such a thing as this tract even exists in the Western world, where we all know the basic Christian beliefs.

Even if we manage to avoid organised religious instruction, after all, those of us who live in societies where Christianity is commonplace are entirely familiar with the highly sensible idea that God sacrificed himself to himself in order to expunge the stain of original sin upon all humanity which was there because God allowed the most persuasive liar in the universe access to God's favourite creations and then they disobeyed God and ate something which apparently made evil suddenly exist or something and God then punished not only Adam and Eve but also arbitrarily decided that their disobedience would now sin-stain all of those first humans' offspring even though the offspring were not the ones who committed the sin but it's all right now because the temporary death of the human-like aspect of God during which that aspect might or might not have visited hell or some place like it freed all humans from the abovementioned arbitrary damnation brought upon us by God because of one bad act by our distant ancestors provided we follow the appropriate rules during our life which may or may not involve cutting off a piece of one's penis or being very respectful towards special little biscuits.

For some reason, many people outside the Western world find it hard to take this stuff seriously.

If you've been marinated in it all your life, though, then you definitely already know about these basic Christian beliefs, along with blatantly ahistorical nonsense like Caesar Augustus bizarrely deciding that for tax and census purposes everybody in the Roman Empire had to return to wherever their distant ancestors lived.

People who don't believe evolution is true - who are often quite convinced that God has communicated the truth of creationism to them via another of those "personal relationship" deals - sometimes ask "if we evolved from monkeys, why are there still monkeys?"

This argument fails for at least two reasons, but applying the same logic to religion does not, because religions usually claim to have invalidated previous faiths.

Christianity, for instance, says it superseded Judaism. But if that is the case, why are there still Jews?

And Islam says it superseded Christianity. But there you Christians still are, and the Jews, and the Muslims. And don't you Abrahamic siblings all just get on like a house on fire. (Or a church, or a temple, or a mosque, the setting-on-fire of all of which is apparently often also strongly encouraged by God in those personal conversations people keep alleging they have with him.)

And all this time the Hindus and Buddhists have been sitting there too, not being persuaded by any of you guys. People convert one way or another from time to time, usually to the great alarm of conservative members of whatever faith they converted from, but the overwhelming determinant of your lifelong religion remains the religion of your parents.

Which, once again, is exactly what we'd expect to see, if all religions were fictional.

If one religion were true, with an all-knowing, all-powerful and benevolent deity, then that religion should be more persuasive. Its followers and prophets should be distinctly different too. You certainly shouldn't see everybody in every faith bumbling around in the same way, and every faith producing the same few great people, few terrible people, and great mass of ordinary people.

And yet, that's what we do see.

Most religious followers have plenty of stories of events that plainly prove that they're on the right track. When I worked with Jehovah's Witnesses, for instance, many of them had stories of encounters with the malevolent spirits that constantly strive to tempt us from righteousness. Some Catholics hold forth about the effectiveness of their various sacramental adornments, many Scientologists have seen their "tech" work wonders, many Muslims think you might as well drive with your eyes closed because they've seen many times that you'll only crash if Allah wills it, believers in reincarnation from the Hindu to the New Age think the evidence couldn't be more clear, evangelicals are surrounded by miracles and portents every day, and umpteen religions claim some great practitioner didn't need to eat or didn't rot after they died.

The closer you look at such claims, though, the more tenuous they become. Most religious claims are exceedingly difficult to test in any empirical way, but the very fact that most religions say they have hard evidence that they are the only correct religion indicates that, as in the case where two men say they're Jesus, most of them must be wrong.

For pity's sake, even the three flavours of Christians whose job it is to mind the place where Jesus was allegedly crucified and interred keep getting into fistfights when someone moves a chair. And heaven forfend anybody shift the Immovable Ladder. I am not making this up.

I also have to quibble with the tract's statement that "all questions demand answers". The question of the preferred sock colour of François Mitterrand does not, to my knowledge, keep many people up at night. And this isn't just me snarking; I find "it doesn't matter" is a perfectly satisfying answer to that question, and to many others, some much more important to religious people than the sartorial preferences of deceased Gallic statesmen.

Take, for instance, the question, "do gods, which do not intervene in the universe in any way, exist?"

The logical answer to this question is "it doesn't matter", because a god who does not interact with the universe is a god who might as well not exist.

This is not the sort of god that Christians believe in, of course. Some Christians believe Jehovah interacts with the world in profound and obvious ways, because otherwise humans and roses and organ music and the laughter of little children and preachers who can cure terrible diseases by magic - though, again, not in any empirically-verifiable way... - would not exist.

Many Christians believe Jehovah stopped performing miraculous party tricks many centuries ago, but that he does still definitely interact with the world, once again because of that direct personal relationship with their deity which they solemnly believe they have. This would be impossible if that deity did not interact with at least the minds of his followers, in some way.

This is a pretty solipsistic justification for belief, though. "I feel God's presence in my heart and mind" is all very well as a justification for your own belief, but it won't convince anybody else unless they independently find such thought processes going on for them as well.

And this certainly isn't a reason for any unbeliever to believe in any particular one of the hundreds of different allegedly-holy scriptures out there. If your only evidence is your God-filled heart, then what answer have you to someone who apparently feels as internally convinced as you, but says that God has called upon him to spread the new doctrine of invisible pink unicorns and eating nothing but geranium leaves, and heretics must be put to the sword?

(Or, of course, someone who starves their baby to death on the grounds that he's insufficiently pious, and then waits patiently for him to resurrect and the murder conviction to thus be quashed. They honestly believed it! Who are you to say the baby won't pop back up any minute now?)

This tract doesn't even make it to the level of Pascal's Wager. All it says is, "We reckon heaven exists. Why don't you want to go there?"

Given the paucity of this question, I shall conclude with the answer I most enjoyed delivering to the more dim-witted Jehovah's Witnesses who asked me, "Don't you want to live forever?" I don't believe it, of course, but at least I was doing them the favour of inserting a new idea or two into their brain.

No, I don't want to live forever.

Forever is a long time. Forever is a trillion trillion trillion trillion googolplex trillion trillion, et cetera, years.

If you could carry one atom at a time, at walking pace, you could move the whole observable universe from where it is to somewhere far, far beyond its borders, and still have made no inroads whatsoever on forever.

God, presumably, has lived, and will live, forever.

Christians seem pretty definite about that.

God needed to keep himself amused.

So he made the world, and maybe many other worlds. And heaven, and that's where he lives, and he'd like you to come and join him.

To be in heaven with him.


He could let you die, but he won't.

Have you ever wondered why God didn't just kill Satan, given that Abrahamic doctrine makes clear that he could have done so any time he liked?

God's not going to let the bastard die.

All Jehovah has left is sharing the misery.

Magnificent marble machines

In which I shamelessly knock off a couple of videos from this page on Matthias Wandel's site.

More at woodgears.ca. Other marble machines, including Matthias' own ones, are here.

Sharp edges are just good aerodynamics

Here's something I didn't know existed.

Behold, the rocket monocopter!

It's a wing on one side, and a rocket pointing horizontally on the other.

Or, in the case of this monstrous one...

...two J engines and a K in succession, as this spinning surfboard wanders the sky looking for heads to lop off.

It doesn't seem very difficult to build a small rocket monocopter, from scratch (a spare R/C helicopter rotor blade is helpful...) or a kit.

It's apparently possible for these things to get themselves into a nice flat autorotation spin on the way down, too, so you don't need a parachute.

Well, that's the theory, anyway.

One-bladed propellers are actually very desirable, essentially because the more blades you have, the more turbulence each blade must cope with from the blades in front of it.

The obvious problem with dropping to one blade is that if it's mounted on a shaft and developing thrust, then that thrust will be off-centre, spinning around the shaft with the blade, and thus ruining the shaft bearings quite quickly. So you only see single-bladed props in oddball applications like these monocopters, and extremely tweaky ultra-speed control-line models, and certain rather expensive ceiling fans.

There are also propeller-driven monocopters, where a motor and prop takes the place of the rocket in the above contraptions. With modern digital control and image-processing systems, monocopters may be useful as unmanned aerial vehicles:

Posted in Hacks, Toys. 2 Comments »

More magnets

The mysterious Professor X, from that post the other day about scaling up little toy sculpture magnet things to evade bans on such toys, has contacted me again:

Now that I'm not headed to bed and can really read the post, thanks again for such thorough and useful info. The comment to your post was useful, too.

I assume that if the sphere size stays the same and the flux factor goes down, they're just not going to be as effective for sculpting because they won't hold as well, and they won't have the same satisfying snap, etc. The lack of a workable alternative is just as good for me as a teaching point as a workable alternative would be; I'll have fun with this. I appreciate your assistance to total stranger.

I find it funny, after reading your post, that the CPSC in its Notice of Proposed Rulemaking says, "Thus, it might be possible for manufacturers to make magnet sets that contain strong magnets so long as the magnets are sufficiently large, although the large size could reduce their utility."

Well, that's an understatement, apparently.

Professor X

Various magnets

To get a, literal, feel for how these things behave, I do strongly recommend you hit eBay and get some cheap magnets there, both the little strong silver ones and the black shiny "rattlesnake egg" type (which can be had as spheres as well as elongated ovals).

The eBay seller I got some of my element samples from, "The Mists of Avalon" (here on eBay Australia, here on eBay UK) has some interesting magnets too, including irregular "tumblie" versions of the rattlesnake-egg type.

Plus, of course, these things really are some of the greatest fiddle-toys ever created. Just don't put them in the same pocket as your credit cards!

I used to also have to warn people to keep strong magnets away from CRT monitors and TVs, but that's way less of a problem these days, of course. To demonstrate rare-earth magnets' their ability to wipe other magnetised things, get a standard flexible rubber fridge magnet of the sort given away as promotional items, scrub it all over with a smallish rare-earth magnet, and behold that it now can't stick to a fridge at all.

This is because those rubbery magnets are set up with a "one sided" array of alternating parallel rows of magnetisation - that's why only one side of them sticks to the fridge, and also why they stick to each other in such an odd, "lumpy" way.

Fridge magnet field pattern

You can also use magnetic field viewing film (a small piece of which can be yours for less than $10 delivered) to see this oddness directly.

When a strong enough external field re-aligns these parallel poles so they all go one way, the essentially feeble magnetic material can no longer hold up own weight.


There's a lot to be said for ferrofluid, too.

The cheapest ferrofluid on eBay is in tiny squeeze sachets, for topping up the coolant in tweeters. But you can get thirty grams for less than $US25 delivered; that's enough to have some fun with.

There are also several dealers selling sealed vials with ferrofluid and possibly also some immiscible liquid inside, to keep the ferrofluid clean and, perhaps more importantly, prevent other objects, people and pets from being stained by it. Regrettably, you can only get some of a ferrofluid stain out of your clothes with a magnet.

Also, if physics demonstrations at all interest you, those little magnets can be great for those, too!

Too much of a good thing

A reader writes:

I've tried to find the answer to this on my own, but I'm struggling. I'm hoping the question will be easy for you to answer and interesting enough that you'd like to answer it.

I teach products liability, so I've been interested in the Consumer Products Safety Commission's notice of intent to ban Buckyballs and other, similar magnet sets meant to be adult desk toys. The CPSC would like to ban magnet sets that contain magnets that have a flux index of over 50 and are so small that they fit within the CPSC's small parts cylinder. Most of the magnets in these sets are 5mm in diameter, although some sets have smaller magnets.

To be too big for the cylinder, the magnets would have to be more than 31.7mm in diameter.

So, to have an intelligent conversation with my students about this product, I need to know what would be the effect on the utility of these magnet sets if the spherical magnets are made too large to fit in the cylinder. These are NIB magnets. Would the magnet sets with larger magnets still work effectively as desk toys, or would their properties change in a way that would make them less effective? Or are they just less fun if they're that much bigger? Any thoughts you're willing to share would be greatly appreciated. And thanks for reading this far.

Professor X (not his, or her, real name)

Oh, man. That would be such a bad idea. So gloriously, horrifyingly, hilariously bad. But possibly rescuable with some serious design changes, on top of the larger size.

On the plus side, making novelty-toy rare-earth magnets more than 30mm in diameter probably would reduce swallowing incidents to zero.

On the minus side, the per-unit bulk price for rare-earth magnets that big is probably about $5, making a set of more than a few of them rather expensive.

And on the second and rather larger minus side, such a toy would hunger implacably for your blood, bones and cartilage.

(I'm not sure what shape this one-plus-sided, two-minus-sided object I'm describing is. Perhaps it's like the skewed dice.)

As a general rule, large NIB magnets are Serious Business and Absolutely Not Toys. They can clamp onto ferromagnetic objects, and especially onto each other, with terrifying force. If all you lose is the end of your finger, you should count yourself lucky.

Every now and then I actually have some application for my old...

Hand-crushing horror

...2-by-1-inch cylinders, or two-inch-square truncated pyramid...

Truncated pyramid magnet

...like for instance finding and extracting the end of a broken felting needle from the enormous ball of shed cat fur which I am making because why not.

When I have such an application for one of those magnets, I treat the damn thing like a 70-year-old hand grenade. I would not even consider any activity that required me to use two of them at once. And they're not even all that big. Sort your eBay search highest-price-first and, among the bulk-lot listings for large numbers of smaller magnets, you'll find some real nightmare fuel. Six-by-four-by-two blocks, for God's sake.

Under the shiny coating, rare-earth and conventional ferrite magnets are also quite a fragile ceramic, so two large NIB magnets allowed to smash into each other can easily, essentially, explode.

Spherical NIB magnets are a particular problem, because the contact patches between them are very small. Little 5mm sphere magnets work as toys because their attraction to each other isn't nearly strong enough to be dangerous, and the coating on the outside (usually silvery nickel) is thicker, proportionally speaking. (I think quality NIB spheres may have thicker-than-normal coatings, too.) But large NIB spheres - like, anything from about 10mm up - start to become a pretty serious pinch hazard, and will damage the coating at their contact points quite quickly.

To get around all this for a toy with large magnetic spheres, you could make the spheres out of something non-magnetic, and embed smaller rare-earth magnets in there. Perhaps a 20mm magnet centred in a 35mm block of plastic, for instance, or multiple little magnets in a plastic block, or just a really, really thick epoxy coating. I don't know how well it would work, but at least it wouldn't actively desire your destruction.

The popular shiny black ovoid "rattlesnake egg" magnets can safely be allowed to fly at each other and chatter together, because they're made from durable artificial hematite, and perhaps a bit stronger than ordinary ferrite magnets, but still not nearly as strong as commonplace neodymium-iron-boron magnets. Magnets of this sort might also be a good choice as "giant Buckyballs".

I continue to strongly recommend that people buy a ton of little rare-earth magnets for pennies on eBay; they really are excellent toys, not to mention useful for all sorts of odd things from hanging up tools to clamping small items until the glue sets.

They're just not for little kids, because little kids are idiots.

(Not Safe For Work, possibly Not Safe For Life, example.)

Posted in Toys. 5 Comments »



Alarm clocks are awful. Get one of these instead.

Even if your alarm clock is one of those Zen alarm clocks with melodious metal chimes, or it's your phone playing New Age music at gradually increasing volume, an alarm clock is still not offering you anything. It's just invading your rest and causing you to start your day with a little slap of sadness and irritation, arguably made even worse by the snooze button's empty gift of a few more minutes of half-sleep. Which you'll probably only spend trying to integrate your interrupted dreams with wakefulness.

(It is, at least, pleasant when I realise for the umpteenth time that I am not, in fact, still in high school.)

Or you may just lie there, living in fear of the return of the cursed alarm.

I shudder to think how much human misery those millions of little morning insults have added up to, over the centuries since humans first invented a water clock that would make a noise at a particular time.

Presuming you can't just rearrange your life so it doesn't matter when you get up, the best option in the pursuit of timed wakefulness is, clearly, a butler. A butler who brings you a cup of tea, even as he murmurs his apology for the regrettable necessity that you be conscious.

(The celebrated Stephen Fry alarm clock seems to no longer be in production, and it would also appear that more people paid for them than actually, strictly speaking, received a product in return. One can only hope that the Bible-verse version of the same product is similarly defunct. I would very much like to see a combination of the two.)

Failing that, what you want is a teasmade.


This one's mine. It's not a particularly elegant or collectible example, but it does the job.

The modern teasmade - the term has become a genericised trademark, in Britain at least - is essentially an electric kettle controlled by an alarm clock. When the alarm time is reached, the kettle element turns on, and a few minutes later boiling water is delivered to the tea-leaves.

Or to anything else you put in the little teapot, for that matter. If you want alarm-clock instant soup or Bovril or anything else you can prepare by putting it in a pot and pouring boiling water on it, you can have that too. (Might be a bit of a challenge eating soup out of the little teapot, though, if there are bits in it too big to exit the spout. You could also make a hot-milk-based beverage in a teasmade. But possibly only once.)

Most Automatic Food Machines, especially the ones that look like the coolest thing in the universe, have problems. They don't work in the first place, or they work only for a little while without unfeasible amounts of maintenance, or they're uncleanable, or their sole desire is to maim or murder their operator.

For every good gadget like the blade meat tenderiser or Aeropress coffee maker, there are a dozen crappy As Seen On TV wastes of time and money.

(There's also a small sub-category of wonder food gadgets that can only work by breaking laws of physics.)

A teasmade is not like that.

It is easy for a tired person to set up of an evening, it does what it's supposed to do without fuss, it has no moving parts except the control buttons, and its cleaning requirements are close to zero.

(Classically, you are never meant to do anything more than rinse a teapot; the accumulating tannin stains are supposed to make the tea taste better, though I'm pretty sure that claim doesn't stand up to double-blind testing. If you've got unusually hard water or use a teasmade for a long time then you may also need to clean lime-scale out of the boiling vessel and tube, but just running the teasmade with water and vinegar in the boiler should take care of this.)

Antique brass teasmade

The earliest alarm-clock tea-makers were created in the late nineteenth century. They were shiny and clockwork, with alcohol burners and a match-striker or other similarly implausible mechanism to light the burner when the alarm went off. These devices were less of a threat to life and limb than one might imagine, but were still less than entirely convenient to operate, and also rather expensive. And, to be fair, if there's one thing that'll wake you up even more effectively than a nice cup of tea, it's a fire on your bedside table.

The modern teasmade is electric, safe and reliable, and quite cheap. I bought mine used on eBay in 2003, and it cost me only $AU37.85 delivered. That was an unusually good deal - one just like it is on ebay.com.au as I write this, for $AU90 plus delivery - but working and pretty-safe-looking used teasmades routinely sell for well under $US100 delivered, and you can get a brand new one for less than 60 UK pounds delivered within the UK, $AU160-odd delivered to Australia, or around $US165 delivered to the States. Or less, if you buy the version with no radio, of which more shortly.

And yes, American buyers are likely to have voltage problems, because the teasmade is largely unknown outside the UK and as far as I know nobody makes a 110-volt one. More about that in the "buying one" section, below.

How it works


As you can see in the above picture, the modern teasmade really is essentially just a combination of an alarm clock - often, as in mine, a clock-radio - and an electric jug. It's quite easy to use.

The alarm clock in my teasmade works in the same way as every cheap plastic clock-radio. You set the time, you set the alarm, you tune the radio, and you select how you want the thing to wake you up.

Teasmade controls

In addition to the standard clock-radio options of an awful alarm noise or a tinny radio, though, my teasmade lets you select "tea" alone. You will then be awakened by the sound of boiling water, and the smell of a mildly caffeinated beverage.

My teasmade is rated at 600 watts at 240 volts, which is on the low side by electric-jug standards; here in Australia our mains electricity is a nominal 230 volts and a usual actual 240, so electric jugs with a power rating of 2000 watts or more are common.

My teasmade's water capacity is only about 650 millilitres - that's about 2.6 metric cups. Or a couple of good-sized mugs, or more than three dainty little teacups. The 600-watt heater takes about seven minutes to boil this full capacity; proportionally less if you don't fill it completely. You should of course take account of this boiling delay when setting the alarm time.

The initial heating process is quiet; it'd probably wake me up if I were sleeping without earplugs, since I'm a pretty light sleeper, but most people would sleep through it. The part where the boiling water is transferred to the teapot, though, is quite dramatically loud, and should be an effective alarm for most people all by itself.

The reason for the noise is the way in which my teasmade, like pretty much all others, transfers the boiling water from kettle to teapot. When you put the filling cap back on the boiling vessel, the boiler is sealed except for a metal tube that goes almost to the bottom of the vessel, and arches over to point at the middle of the lid of the...

Teasmade teapot

...distinctive hole-topped little teapot. (If you find a junk-shop teapot that looks like this, you now know where it came from.)

When the water boils, the pressure of the steam pushes the water through the tube and into the pot. It takes no more than ten seconds for my teasmade to transfer a full pot-worth of water through the rather narrow tube. Hence the noise. When the reservoir's empty, it heats above the boiling point of water and a thermostat shuts off the heater. (There's also a switch that disables the heating element if the teapot isn't in place, so night-time absent-mindedness will not result in an unconfined spray of boiling water the next morning.)

If you need more of an alarm to wake you up then, ideally, you'd be able to set the horrible alarm noise or irritating radio station of your choice to go off when the water transfers, or even after the tea's had a few minutes to steep. But my teasmade can't do that; the alarm/radio goes off when the heating element turns on, at which point a single cup of tea is at least five minutes away, and a full pot is at least seven.

Some teasmades have more sophisticated alarm settings, so the alarm can go off when the boiling is completed, not when it starts:

OK, that alarm takes us straight back into the Land of Horrible Awakenings. But at least there is tea.

Going along with its cheap-clock-radio nature, my teasmade has no backup battery, and reverts to that good old flashing "12:00" and no memory of previous settings if there's even a momentary power cut. You can solve this problem by running the teasmade, and for convenience also your bedside lamp, from a small uninterruptible power supply. A pretty beefy UPS will even be able to run the tea-making element; a cheap one won't be able to do that, but will at least ensure continuity of timekeeping if the element doesn't try to click on from UPS power.

I'm hardly an authority on teasmades, though; there are a lot of different models, even if you disregard the pre-electric W. Heath Robinson versions.

(Image source: Flickr user James Mooney)

Here's a Goblin with a removable boiler, as well as teapot, presumably for ease of filling.

(Image source: Flickr user James Mooney)

(Image source: Flickr user Martin Deutsch)

I wish mine had a TEA NOW button.

Teasmade with
(Image source: Flickr user leo.j.turner)

Another picture of the same model of teasmade, or at least one with the same buttons. It appears to have won an award. Good for it.

Teasmade with
slightly lopsided lamp
(Image source: Flickr user MarkyBon)

This one just screams Fawlty Towers.

(Image source: Flickr user gruntzooki, a.k.a. Cory Doctorow)

Another just like it, and some others, on display in the London Science Museum. It's apparently circa 1945.

The integrated lamps can be rather nice:

Museum teasmade display
(Image source: Flickr user ebbandflo_pomomama)

Teasmade with top
(Image source: Flickr user Simon Harriyott)

This one looks as if it ought to be mystifying Jacques Tati in Play Time.

Buying one

A simple search for "teasmade" (which may or may not correctly geo-target to your country; here the same search is on eBay UK, and here it is on ebay.com) gets 20 relevant hits on eBay.com.au as I write this, plus a few isolated teapots and a Bjork remix with "Teasmade" in its title.

There are some decent deals there, but I probably got my teasmade so very cheaply - under $AU40 delivered - because it was described as "Alarm clock/radio with teapot -RARE", which barely describes it and is almost impossible to search eBay for. I've no idea how I ever found it.

Even if all you throw into the eBay search box is some generic "tea maker" sorts of terms, it's pretty much impossible to filter out umpteen ordinary electric jugs, teapots with infusers in them, teapot-shaped kitchen timers and so on. Here's my best effort at making such a search across the whole of eBay.com.au with possible geo-targeting to other eBay sites; if that doesn't work, here's one for ebay.co.uk and here's one for ebay.com.

The easiest way to get a teasmade today is to just buy one new. For a while I think this may have been impossible unless you found a dealer with "new old stock", but now it's quite easy to buy a Swan teasmade online.

Swan teasmade

You may or may not care for the Swan's magic-lantern styling and LCD analogue clock, but on the plus side, you know the appliance hasn't been sitting in someone's garage for fifty years, maturing into a truly world-class fire hazard.

The Swan teasmades list on their site for £79.99 (about $US128 or $AU124, as I write this) ex delivery. They don't ship outside the UK, though.

The Swan teasmade is also on sale at this Union-Jack-waistcoat of a site, which is very excited to announce that the "Teasmade Classic is now £48.99 and the Radio Teasmade is now £69.99!". But they, also, only ship within the UK.

There are Swan teasmades on eBay; a US buyer could get the basic no-radio model for $US132.05 plus a mildly suspicious only $US6.00 for shipping, and an Australian shopper could get the same model for $US142.05 delivered.

That's not cheap, but at least the Aussie shopper would only need a plug adapter to connect a UK-sourced teasmade to Australian mains power.

(Until quite recently, it was normal for UK appliances to come with a power cable that terminated in bare wires, because the UK contained an incompatible mixture of the old BS 546 and new - in the sense of "after World War II" - BS 1363 wiring and plug standards. You had to buy a plug separately and screw it onto the cable yourself, or get someone in the shop to do it for you if you were a wuss. Nowadays BS 1363 is dominant enough that I think pretty much all UK appliances come with a BS 1363 plug moulded onto the end of the cable. Chopping that plug off and replacing it with one to suit your own country's mains, so you don't have to use an adapter, is unwise if you don't know what you're doing, but is legal in most countries.)

If you live in the USA, Canada or some other 110-to-120-volt country, though, you have a problem. Some teasmades wired for 110V are alleged to exist, and converting one wouldn't be an insoluble problem for an electronics hobbyist or repair-person, but you ain't gonna get one off the shelf.

So there's nothing stopping someone in the Americas from buying a teasmade from the UK or Australia, but it'll be the wrong voltage and you'll have to run it from a quite beefy step-up transformer.

Your beefy step-up transformer will very probably be an autotransformer, and very probably come with a piece of paper listing a wide variety of devices they strongly recommend you never plug into it on account of autotransformers' poor isolation qualities. A teasmade is likely to fall into at least two of those forbidden categories.

That said, two-pin sockets and cheater plugs do not yet seem to have killed most of the American population, and those are more straightforwardly dangerous than a teasmade running from a step-up transformer. Modern teasmades also have no exposed metalwork, so you're not really living too dangerously if you use one from a step-up transformer. I'd do it. But I am known for making poor decisions.

You can also get fully electrically isolated step-up transformers; they're more expensive, but solve the safety problems. And if your American house has a 240-volt circuit for a clothes-dryer or other high-powered electrical appliance, you can just plug the teasmade into that. (Running an extension cord from the one 240V outlet in the bathroom all the way to your bedroom may negate the safety benefit.)

The frequency of US 240V will be 60Hz instead of the 50Hz the teasmade expects, which will cause old-style electric clocks to run six-fifths as fast as they should. If you get an old teasmade with an analogue clock then there's a good chance it depends on the mains frequency to keep time, and will thus be essentially useless from the wrong frequency. You could run it from a frequency converter, but by now we're getting well out into the crazy-weed.

As long as there's no mains-synchronous clock in your teasmade, a different mains frequency shouldn't be a problem. A newer teasmade with a digital clock will very probably have a quartz oscillator that's immune to mains frequency changes.


By this point, American shoppers intrigued by the teasmade idea but disinclined to subscribe to British Appliance-Fancier Monthly will probably be thinking there must be a simpler way to do this. I mean, you could just plug an electric kettle into a timer switch and get something approximating the same functionality.

It occurs to me that if you get a coffee-maker that has a timer function, put tea leaves in it in place of coffee (and, if you want to get fancy, also replace the paper filter with a mesh strainer screen), you could get very close to a teasmade's functionality without all of the international-voltage bother.

The design of the typical modern no-moving-parts bubble-pump coffee-maker (which, incidentally, uses as a pump the same sort of device that propels a pop-pop boat)...

...is not ideally suited to making tea, but it'd more or less get the job done. A coffee-maker may not quite make Tea According To Orwell, but I'd drink it.

(Oh, and cheap drip coffee makers' primary purpose appears to be to make coffee snobs almost as apoplectic as percolators do, but a teasmade actually makes pretty close to optimal tea. It doesn't pre-heat the teapot, which is a mark against it, but it does deliver really scalding water onto the tea leaves, which is generally agreed to be Correct. Coffee benefits from being made with less-than-boiling water; tea does not. The fact that water boils at only 174°F at 20,000 feet {79°C at 6100 metres} is clearly a far greater problem for British mountain-climbers than any piffling shortage of oxygen.)

Cheap coffee-makers with timers require you to reset the timer every night, because they can't tell whether there's already coffee in the carafe or not, and want to avoid disasters that a forgotten full carafe could cause the next morning. (Leaving the water reservoir empty shouldn't be a problem, though, because even the very cheapest of coffee-makers should have a reliable overheat cut-off.)

You'd think you could get a coffee-making teasmade-analogue with an actual alarm-clock brewing function for a reasonable price, but I'm not sure if you can. I think you can do it with expensive plumbed-in models like this one, but few mere counter-top models seem to have such a feature.

I think this inexpensive Black & Decker model may qualify, though. I managed to find a manual for it online and it does seem to have a repeating alarm-coffee function. If you definitely know of such a thing, please do tell us all about it in the comments.

(On the subject of different approaches to the problem, check this out. Once again, some concept designer has supported my previously-expressed opinion of the breed, in this case by reinventing the teasmade and making it much, much worse. Apart from apparently being carefully designed to set itself on fire from the middle out, this concept design expects you to, first thing in the morning, drink tea out of a hemispherical E-Z Spill(TM) cup with no handle. This design also requires you to put a tea bag in cold water the night before and let it sit there for hours before the water is heated, which I can only presume will cause the ghost of Queen Victoria to manifest, reach into your chest and crush your worthless heart.)