Stormglass

[MRC_Hans]

I just bought a stormglass (not an old one, but a nice replica). I already have a collection of barometers, so this is somewhat relevant. The stormglass is an invention from cirka 1750 and consists of a hermetically sealed glass container with a chemical solution in it. It is supposed to predict weather changes by the look of the crystals forming in it. I have not been able to find any scientific explanation for its function, but it seems to have at least some merit to it.

I'll be interested to hear if others have any experience with these devices, and I'll report any interestin findings I may have with mine.

There is some information here:
http://www.pmicro.kz/MISC/UFL/Almanach/N1_96/StormGlass.htm

Hans

[MRC_Hans]

OK, a short report after observing this device for a few months:

On arrival (after having been bumped around in the bood of my car for a couple of days), there was only a sediment of small crystal fragments at the bottom of tha glass.

After standing untouched for a week or so, a small feather crystal grew. The weather was average.

Then came a long hot period. During this, the feather neatly dissolved. Nothing more happened.

After the hot period came a quite abrubt change to cooler, windy and rainy weather. After the weather change, feather crystals began to grow, and almost filled the glass. This took a couple of weeks.

Recently, weather has become a little warmer, and the crystals are receeding.

Conclusion: The Stormglass has no predictive value for the weather in a household. It seems to respond only to temperature change and only slowly. The way it is constructed, this is not surprising, as temperature seems to be the only external influence on it.

Long-term temperature changes may have a predictive value on a ship at sea, so anecdotical accounts of storm glasses yielding useful predictions onboard ships may have some merit.

Hans

[Ove]

As far as i recall it is supposed to react to atmospheric pressure, sorta like a barometer and therefore it SHOULD be possible to make some predictions based on it. But hey, who can predict anything based on ONE reading. To make a weather prognose you need dozens of readings from many places around the globe. True, if your barometer drops rapidly it is a fairly good indication that bad weather is coming and vice versa but still...

[MRC_Hans]

The glass is sealed, so atmospheric pressure seems out of the question. Anyhow it should have little effect on something in a fluid. I don't know if the seal is diffusion thight; if not, the relative humidity might also influence it. Otherwise, all that is left is temperature. --- And magic, of course ;) .

Predictive value is one thing. Even a barometer requires some meteorological insight to use predictively, but so far, I have just been trying to discover any correlation with present weather whatsoever.

Hans

[fishbait]

Originally posted by MRC_Hans
The glass is sealed, so atmospheric pressure seems out of the question. Anyhow it should have little effect on something in a fluid. I don't know if the seal is diffusion thight; if not, the relative humidity might also influence it. Otherwise, all that is left is temperature. --- And magic, of course ;) .

Predictive value is one thing. Even a barometer requires some meteorological insight to use predictively, but so far, I have just been trying to discover any correlation with present weather whatsoever.

Hans

Could exposure to light be a factor? The amount of ultraviolet maybe? Cloudy days = less light. Just a thought.

Perhaps you might cover it or put it in a closet away from light just to see what effect that might have.

Also, you mention the "weather in a household". Wouldn't it be better to keep the thing outside ? Otherwise, you are measuring the "weather" inside the house, are you not?

BTW, where can I get one of these? I'm a weather watcher and this interests me. Maybe I'll do my own observations. But, It'll have to wait for Spring. Winter is coming on here in the wild mountains of New York.

[jj]

Originally posted by fishbait


Could exposure to light be a factor? The amount of ultraviolet maybe? Cloudy days = less light. Just a thought.

Most glass allows very very little ultraviolet through, and that affecting a crystal structure would seem pretty unlikely, too.

Perhaps you might cover it or put it in a closet away from light just to see what effect that might have.

I'd try in the fridge for a week, and then in the outflow from the fridge for a week. DO NOT FREEZE IT THOUGH. !!!

Also, you mention the "weather in a household". Wouldn't it be better to keep the thing outside ? Otherwise, you are measuring the "weather" inside the house, are you not?

Depends what it measures. I suspect it's temperature, in which case you're right. If it is sensitive to barometric pressure, which I can't understand very well if it's sealed and full of liquid, then that is going to equalize via the many leaks in any real house.

BTW, where can I get one of these? I'm a weather watcher and this interests me. Maybe I'll do my own observations. But, It'll have to wait for Spring. Winter is coming on here in the wild mountains of New York.

My guess is that it's a supersaturated solution. When the temperature goes down to the point that it's unstable, a crystal grows. When it goes up to the point where the crystal is unstable, it disappears.

There would generally be some hysteresis, because in general the crystal won't start forming even beyond saturation until it forms a nucleus, and then the formation will go gangbusters until it gets back to saturation...

As soon as it warms (generally higher temprature would mean more can dissolve, i.e. saturation goes down, although I believe things can go counter to this, oh I mean solids, gasses certainly do go counter to that) the saturation will go down, and it will start to dissolve uniformly all over.

[EvilYeti]

You people really need to try Google sometime. Its just the bees-knees.

Stormbottles (http://www.barometers.com/stormgla.htm)

Here's the legend

Clear liquid = Bright weather
Crystals at the bottom = Thick air, frost in winter
Dim liquid = Rain
Large flakes = Heavy air, snow
Threads in upper portion of liquid = Windy weather
Small dots = damp weather, fog
Rising flakes = wind in the upper air regions
Small stars = In winter bright, sunny days

P.S.

Ok this sounds like BS
more stuff (http://www.orgonelab.org/cgi-bin/shop.pl/page=yweather.htm)

[jj]

Originally posted by EvilYeti
You people really need to try Google sometime. Its just the bees-knees.

Stormbottles (http://www.barometers.com/stormgla.htm)

Here's the legend

Clear liquid = Bright weather
Crystals at the bottom = Thick air, frost in winter
Dim liquid = Rain
Large flakes = Heavy air, snow
Threads in upper portion of liquid = Windy weather
Small dots = damp weather, fog
Rising flakes = wind in the upper air regions
Small stars = In winter bright, sunny days

P.S.

Ok this sounds like BS
more stuff (http://www.orgonelab.org/cgi-bin/shop.pl/page=yweather.htm)

Cool....

Wonder if temperature differential across it affects the crystal growth.

Now, as far as really WORKING, well, that's a different issue. :)

[EvilYeti]

Originally posted by jj


Cool....

Wonder if temperature differential across it affects the crystal growth.

Now, as far as really WORKING, well, that's a different issue. :)

I'm guessing, if it works at all, that is sensitive to both temperature and pressure changes.

Otherwise its just a bad thermometer or barometer.