Chaney Instrument 00795 User Manual

Historic “Storm Glass” Barometer

History

The Storm Glass, or Goethe Barometer, is regarded as the oldest
barometer in the world. Although Johan Wolfgang von Goethe is
sometimes credited with its invention, one was found in his bedroom
after his death, there is evidence that the Moors used similar
instruments during the 8th century. Also called Thunder Glasses,
historians believe the early settlers sailed to the Americas using this
rudimentary barometer.

Using the Storm Glass

Each Storm Glass is hand blown and accurately forecasts changes in the
weather hours in advance. The Storm Glass should be filled with distilled
water which decreases the chance of streaks being left on the glass.
Using the enclosed tools filling the Storm Glass is a simple procedure.

1) Fill a container will water

2) Add food coloring to the water to make it easier to see in the Storm
Glass. Any color will do.

3) Place the long injection tube onto the end of the syringe.

4) Fill the syringe with the colored water.

5) Insert the injection tube into the spout of the Storm Glass. The
tube should go completely down the spout and stop at the top of
the glass chamber. DO NOT INJECT THE COLORED WATER AT
THIS TIME.

6) Hold the Storm Glass with one hand while holding the syringe with
the other. Turn the Storm Glass upside down.

7) Slowly inject the colored water into the chamber of the Storm Glass
until it is about half full. See illustration above.

8) Remove the injection tube from the main chamber & spout.

9) Turn the Storm Glass back to its upright position and set it on a
flat surface

The water should be about 1” up the spout of the Storm Glass. If the
water is not at this level, fill the syringe with air and insert the filling
tube back into the top of the water chamber. Do not turn the Storm
Glass upside down for this procedure. Inject air into the chamber.

Water will rise up the spout and may overflow. You may want to do this
over a sink and have a cloth or per towels handy for clean up. Once you
remove the injection tube the water should be further up the spout.
Once filled the water in the spout will immediately respond to changes in
barometric pressure. No adjustments are required once the glass has
been filled. Some evaporation may occur over time and additional water
can be added as necessary.

Reading the Instrument

Variations in barometric pressure are associated with weather systems
and these changes are immediately shown by the level of the water in the
spout. A low water level in the spout indicates “High Pressure” and fair
weather can be expected. A high water level in associated with “Low
Pressure” and forecasts poor weather conditions. On cases of severe
weather or major storms the water may even run out of the spout.

How it Works

High and low pressure systems that bring about changes in the weather
have a “weight” associated with them. When the Storm Glass is filled the
air pressure in the main chamber is trapped and held constant. Changes
in atmospheric pressure are indicated by the rising or falling level of the
liquid in the spout.

The Storm Glass does not indicate exact barometric pressure, as would a
numeric barometer, but it is an accurate monitor of changes in air
pressure. It is accurate enough to display the change in air pressure
between the basement and attic of the same house.