How does storm glass work?

how does a storm glass work

How does storm glass work?

Storm glass, also known as a weather glass, has been around for centuries and is still used today to predict the weather such as Weather station.  In old days storm glass is also known as home Weather station.

Weather forecasting technology has changed dramatically over the years but storm glasses are still commonly used by many people. Storm glasses come in many shapes and sizes and can contain different liquids such as alcohol. The type of liquid in your storm glass will determine what color it changes to when exposed to hot or cold temperatures.

A storm glass is a type of glass that appears to be colorless or blue in daylight, but takes on very different colors when exposed to changes in atmospheric pressure

Let’s take a look at what causes the change in color, how the original invention came about, and some interesting things you can do with storm glasses!

Storm glass is created by filling an ordinary wine glass half full with water (or alternatively alcohol) and dissolving one teaspoon of camphor (the chemical name is hexane; it can also be found in mothballs) in it. Next, ¼ teaspoon of liquid cobalt chloride is added, followed by a layer of silver chloride or silver bromide. The storm glass is then stoppered with cotton wool soaked in nitric acid. Once the storm glass is assembled, it should be left for at least two weeks to give the chemicals time to interact with each other.

The liquid cobalt chloride is blue, while the liquid silver chloride is colorless. When the camphor is used as a separating agent between these two layers of liquid, it takes on a milky white appearance due to its refractive index being higher than that of both solutions surrounding it.

The separation of the solutions causes light passing through the storm glass to bend, thus creating differing colors that vary based on atmospheric pressure. A low atmospheric pressure causes the liquid cobalt chloride to sink, exposing more liquid silver chloride for light to pass through. This results in a green color being seen in the storm glass. As atmospheric pressure rises, both layers move up, causing more of the camphor layer to be exposed. This creates a color similar to that of blue sky or water, which is why it is known as “the sailor’s weather glass.

The idea behind these “storm glasses is straightforward: Raindrops and other moisture in the air attach to particles of dust and dirt in the atmosphere and fall to the ground as rain. The same mechanism is thought to occur on house windows, making them cloudier as rain approaches due to increased condensation on their colder surfaces. The only difference with “storm glasses” is that they are sealed containers so all of this condensed moisture falls down inside them rather than outside. And if the moisture forms a layer of dew on the bottom of the sealed container it will be more likely to evaporate and escape. Thus, these glasses are expected to get cleaner and cleaner as rain approaches and more cloudy or opaque as it passes. storm glass is not as effective as different types of weather station.

Do they really work?

The original storm glass was invented by John Cumstance, a British physician and chemist living in France. He published his invention of the storm-glass (cracked globe), or “Cumstances’ telluric flasque,” during the late 17th century. It was constructed so that when storms would approach, it would turn red and emit a smell like rotten eggs, anticipating bad weather and other atmospheric phenomena. Modern versions of this contraption still exist today.

The weather seems to be playing tricks with our minds, and we’re all desperate for a glimpse of what’s ahead – without having to wait any longer than usual. Storm glasses, also known as hurricane glasses or barometers (depending on where you are), are said to predict the weather by gathering information from the air pressure. And while it might not always deliver the answer you’re looking for, it does seem to be one heck of an indicator. We’re not saying that if there’s a storm glass reading of 17 inches that you have less than 2 hours left before your home is destroyed. But it’s worth checking your glass just in case.

In the weeks or days before a storm, certain clear or white glass objects will become cloudy. Some people think this indicates an impending storm. 

But do they actually work? The short answer is no or maybe not or sometimes. More on that in a bit.

A laboratory test (Schuster & Schuster, 2010) that analyzed how “storm glasses” might work was published in 2010 by two chemists from Germany (Schuster & Schuster, 2010).

Storm glass accurate

How to reset a storm glass?

Here is how to reset a storm glass:

1) Fill the glass with distilled water. 

2) Add sea salt to the water in the glass. The mixture should be diluted enough so that you can see through it when you look through it. 

3) Now, lay down your wet finger onto the surface of the liquid in the glass and trace two lines – one at both ends, but off-center. 

4) Wait for about ten minutes before looking at what has happened inside of your water mixture in the space between these two lines. 

5) Then, take a good look at the water you have just traced with your finger. 

6) If you are able to see your fingerprint on the surface of the water, then it means that there is not enough humidity in the air or that there is too much dryness or warmth in your environment. It also means that things are about to change. 

7) If there are no fingerprints present on the surface of the water after 10 minutes, then it means that there is too much humidity in your environment and things are changing for the better. 

8) To know whether or not you should do something about these changes, just watch how many droplets have dried up on either side of both lines simultaneously. If the number of droplets increases significantly, then this means that something is about to change for the worse. 

9) If this is the case, you would advise you to stop what you are doing and go take a walk around outside for about 20 minutes or so. You should be able to identify these changes by 10:00pm. 

10) If nothing bad happens after your 20 minutes of walking outside, then it means that there are no changes in your environment and you would be better off continuing with what you were doing when initially noticing changes in your environment. 

If you are looking for thermometer Then check out our buying guide on best Indoor outdoor thermometer.

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Before purchasing a storm glass, do some research and make sure it will work for you by comparing different storm glasses based on their features and characteristics. Check customer reviews before buying one.

If you’re looking to buy a storm glass, have a look at our storm glass buying guide.

Heat and tilt the storm glass gently enough for the crystals to melt entirely takes around 15 minutes. A tank of entirely clear liquid with no crystals or sand in the centre is required. Allow for complete cooling before gently re-inserting the storm glass into the container. 

Even when the weather radically changes, crystals can stay that way for weeks, if not months. If you discover that your storm glass is not changing, it is critical that you reset it.



A storm glass, also known as a weather glass or a camphor glass, is a glass tube containing a mixture of ammonium chloride, potassium nitrate, camphor, water, and alcohol, which produces a generally transparent liquid in which various types of white crystals grow and disintegrate on a regular basis.

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