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Posts tagged ‘Weather’

Crystal Storm Glass – The Attractive Weather Forecaster that doesn’t.

Even in the modern age weather prediction is a chancey game. Despite the power of satellites, weather radar, and host of other modern instruments the weatherman still doesn’t always get it right.

But in early ages it was even worse. Naturally they lacked such modern electronic tools that we have so they desperately sought out any device or gadget that would help them predict storms or other weather. This wasn’t a matter of the danger being getting a little wet, this was life and death in many cases. As much as weather can still kill these days, it was much worse when a sail-powered ship might head into a fierce storm that could cause damage or loss of life.

Devices such as early barometers and static detection might help, but what people wanted was something that could predict the weather.

For a while, some thought they had found one. The only problem was: they were wrong.

Enter the Storm Glass. These were sealed glass tubes or other shapes. Inside was a mixture of water and other chemicals (usually camphor being the most common).  It isn’t known who invented or developed the Storm Glass, but one Admiral Fitaroy was the biggest champion for their use to predict storms in the 19th century. The British Crown went so far as to supply them to the various British Isles.

There were even charts or lists produced to show what the various types of crystals indicated the weather would be.  An example from Admiral Fitzroy

  • 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.

It was all nonsense, of course. Although the various formations of crystals could seem to be a reaction to the weather, the fact was the only thing the crystal formation could indicate was a change in temperature. This was confirmed in 2008 by a paper in the Journal of Crystal Growth.

Once people realized that the Storm Glasses were of little use in weather prediction they were ignored or removed.  A few holdouts produced artisan versions but the idea was mostly abandoned. However, when the ‘MAKE’ movement started producing instructions for making home-made versions people started to clamor for a more aesthetically pleasing version they could display at home or on a desk. This has resulted in the versions you see today. Although tube versions still exist, there are also teardrop shaped units, as well as glass swans, ovals, or whatever else the glassamkers think will look good.

So a failed weather predicting device becomes home art. Hey, it happens!

Want to buy a Storm Glass?


Galileo Thermometers – How they work and how to read them.

As far as temperature measurements go, the most beautiful way to measure it is with a Galileo Thermometer. The attractive glass tubes with floating balls that change over time and temperature ever so slowly and gracefully.



Its not so much the heat, but the…Dew Point?

We’re in the middle of a very nasty heat wave here in Philadelphia (where Spectrum Scientifics is based). Temperatures are expected to reach 100 degrees (F) before the end of the week.

One thing we have noticed in various accounts of the weather is that most forcasters and weather reports don’t really have an accurate measure of just how uncomfortable the hot weather is when you factor in all the moisture in the air. You’ve doubtless heard the phrase “its not the heat, its the humidity” but measuring humidity doesn’t always give us a sense of how it feels to us. You get a percentage figure, but that doesn’t say much.

Forcasters have tried to factor in humidity by using what they call the ‘heat index’, but this is never a good index. A person standing in dry desert heat at 98 degrees is not having the same experience as a person in 90 degree weather with high humidity. “Heat index” seems to be one of those measurements so people can quote high numbers to say how bad things are. “Wind Chill” is another such figure and based on some poor information (it assumes you are not wearing clothes, for example), but more on that  figure another time.

So what is the best figure for determining how comfortable or uncomfortable you are going to be? The best indicator is actually a little measurement call the Dew Point.

The Dew Point is the actual temperature and object has to be for moisture in the air to condense. Think of how you take a cold soda out of the fridge and moisture forms on it. That soda is chilled and well below the dew point, so the moisture in the air turns to liquid in it.

Dew Points actually can be a better indicator of how comfortable a person will actually be, since it can cover lower temperatures where the humidity is high (clammy is the unofficial term).  When the Dew Point is below 60, most people are quite comfortable. From 61-65 it can be a little uncomfortable to be in, and a Dew Point above 65 is just going to make people unhappy.

Even Dew Point is hardly a perfect measurement. Things like clouds, wind, and other weather factors can make a somewhat higher Dew Point seem more tolerable than normal.  But at least the Dew Point is not a high number set up by TV weathermen to impress people with big numbers.

So remember to watch the dew point, and keep yourself hydrated!

Dew Point as of this writing: 72 Degrees