Friday, January 20, 2006

Admiral Fitzroy's Stormglass

stormglass
Well, my latest toy arrived by UPS yesterday afternoon. And I am sitting here and still trying to puzzle out Admiral Fitzroy's stormglass.

Or, as it's sometimes called, a stormbottle. (Stormbottle— I love that word!) Talk about a funky weather forecasting device! Brass, nearly six inches tall. Chemicals sealed in a glass tube. The whole thing weighs about one pound. And it's supposed to give you a fairly reliable forecast of weather over the next 24 to 48 hours.

Surfing around, we learn that the stormglass dates back to around 1750. Nobody knows who invented it, but by around that time such devices were for sale at a shop called "Under the Goat and Compasses" at Old London Bridge. The stormglass was popularized during the 1800s by Admiral Fitzroy (1805-65), commander of the HMS Beagle— it was one of the devices Fitzroy used during the Darwin Expedition.

The liquid in the glass is a mixture of distilled water, ethanol, potassium nitrate, ammonium chloride, and camphor. To be lazy and lift the rest of my homework straight from Wikipedia:
During the historic voyage, FitzRoy carefully documented how the storm glass would predict the weather:
  • If the liquid in the glass is clear, the weather will be bright and clear.
  • If the liquid is cloudy, the weather will be cloudy as well, perhaps with precipitation.
  • If there are small dots in the liquid, humid or foggy weather can be expected.
  • A cloudy glass with small stars indicates thunderstorms.
  • If the liquid contains small stars on sunny winter days, then snow is coming.
  • If there are large flakes throughout the liquid, it will be overcast in temperate seasons or snowy in the winter.
  • If there are crystals at the bottom, this indicates frost.
  • If there are threads near the top, it will be windy.
A storm glass works on the premise that temperature and pressure affect solubility, sometimes resulting in clear liquid; other times causing precipitants to form. However, the method by which this works is not fully understood. Although it is well-established that temperature affects solubility, sealed glasses are not exposed to the pressure changes that would account for much of the observed behavior.
My stormglass was made in Denmark by E.S. Sørensen. I'm still trying to dope out certain points from the often obscure and sometimes contradictory material I've been finding online. (Don't you just love the cacophony that is cyberspace?!) In particular, you'll see I've installed my stormglass just inside my (north-facing) kitchen window, as some sites recommend; I suspect I ought to (as other sites recommend) move it outside, where I should hope the alcohol content will keep it from freezing.

Oh well. Mechanical ingenuity and I do not mix. This is what they call a "learning experience"...

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7 Comments:

Anonymous Lucy said...

Man! I SO need one of those. Assuming that they work. Do they actually work? Or are they just really cool to look at? We'll be wanting updates on your stormbottle experience :)

Fri Jan 20, 02:16:00 PM  
Blogger Paul Burgess said...

Lucy, that I'm still attempting to determine. Honestly don't know if it works or not. But in any case, it is cool...

BTW, I've gone and moved the stormbottle, so that it's exposed directly to the outdoor air. I installed a hook on the underside of a window sash, and hung it from that hook. Now it's hanging in between the inner window and the outer window— or rather, I left the outer window up, so that nothing but a wire mesh screen separates the stormbottle from the great outdoors.

So I'm still able to keep an eye on it from my kitchen table, and I can bring it back "indoors" at any time by simply raising the inner window and removing the stormbottle from the hook.

The sudden temperature drop of putting it out there in the cold air has caused the camphor solution to pretty well cloud up. I figure there's a high enough alcohol content to keep the mixture from freezing. I hope! And it's only about 30° F. out at the moment, and not likely to get much below 25° tonight.

My game plan is to leave the stormbottle out there, and see what, if anything, I can make of whatever changes it may undergo.

Sat Jan 21, 05:44:00 PM  
Blogger John said...

Any update on the stormglass as a weather predictor?

Thu Nov 16, 12:52:00 AM  
Blogger Paul Burgess said...

Yeah, I went and hung the stormglass so it was directly exposed to the outdoor air. And kept an eye on it there over these past ten months.

If you go by the simple rule of "clear fluid means fair weather ahead, crystals growing in the fluid mean precipitation in the next 24 hours," then the stormglass is actually a fairly good weather predictor. Not infallible, but at least as good as the weatherman, if not indeed a notch better.

Thu Nov 16, 08:14:00 AM  
Blogger ruggers said...

19:07
I recieved mine as a christmas present and at the moment it is working as predicted.Just have to wait for a change in the weather. Will keep you posted.

Fri Dec 26, 01:07:00 PM  
Blogger Robert said...

I make storm glasses. there are many theories why these work the way they do. all are wrong. quantum tunneling, (forward and reverse biased diodic effects) and the indothermic nature of potassium nitrate/ammonium cloride result in two basic formations. di-tri-hedral crystals and linear fern forms. once and a while there will be a filament. i have found that natural camphor is better and using a larger bottle makes for some interesting formations.

what is happening in the bottle is being effected by the same solar winds(sub atomic particles that effect our weather. some time the storm glass will indicate rain, but you also have to have moisture. there have been times predicted by forcasters, of rain - but not a drop, when the glass is clear of snow flakes. I have a special mixture that actually fogs up and forms clouds with flakes falling from the bottom of the cloud. Skip subspaceone@gmail.com

Fri Sep 11, 11:26:00 AM  
Blogger SYD said...

It does work.
First, put it away from windows.
second, away from direct sun light.
third, away from draft coming from open window.
Finally, leave it still and don't shake it. With days after a week or so it will start it's magic and be more accurate when it reach it's final step.
Then you will have what to expect from your StormGlass.

Tue Nov 15, 11:33:00 AM  

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