A barometer is a scientific instrument that is used to measure the pressure of the atmosphere in a certain area or environment. The atmosphere is what we call the layers of air that surrounds the planet. This layer of air is acted upon by gravity and is thus pulled downwards. This downward pull causes what we call atmospheric pressure or barometric pressure. As such, the denser the atmosphere in a specific area is the greater the pressure exerted, the lighter the atmosphere, the lesser the pressure.
How then, does a barometer measure this atmospheric pressure? At its most basic, a barometer is made from a glass tube that is sealed at the top, the bottom part of which sits in a basin of mercury. As the atmospheric pressure increases, it affects the mercury in the basin and forces it into the glass tube. The higher the pressure, the higher the level of mercury in the glass tube. This allows us to measure the atmospheric pressure in a given place.
How does knowing the atmospheric pressure in a certain area be of use? It can be used to predict the weather in a given area in the short term. If the pressure is low, it is more likely that the atmosphere cannot drive away the clouds and as such, rain is more or less imminent. High pressure means the clouds cannot gather and it would be a dry, sunny day. It’sa helpful thing to know, especially if you are going on a picnic or a day trip to the country.
The Invention of the Barometer
The barometer as we know now was invented by Italian inventor Evangelista Torricelli in 1643. Torricelli was a former pupil of the well-known Italian astronomer Galileo Galilei. The barometer came about from his observations of how the level of mercury in a container will change from day to day. This led to the experiment involving the basin of mercury and the glass tube. For the longest time, this was how barometers were made.
The Barometer at Home
At first, the barometer was only used by the scientific community. However, this started to changeduring the late 1600s when barometers started to appear in people’s homes. Granted, in the beginning, it was mostly the rich that acquired them. Mercury was very expensive at the time, so only the truly wealthy can afford to have barometers. This went on till about the 1800s when the middle class started procuring them for their homes. Barometers became a household item at this time,especially in England where there was a great preoccupation with the weather.
These household barometers were not just tools for the home, they were also decorations. As such, were made quite ornately mostly following the design aesthetics of the period. The very first types of these barometers were of the stick variety. It was the same as before, a glass tube with a container of mercury at the bottom, but these were mounted on a piece of wood which in turn would be placed on a wall of the house. The wood they were first mounted on was walnut, but as time progressed, they were mounted on more exotic timbers. Mahogany, rosewood, and pearlwood were known to be used among other types of wood. Later still, lacquered wood was used. They also became very embellished much the same way furniture and clocks were at the time.
Another type of household barometer was introduced soon after the stick barometer. Instead of a column of mercury, it had a dial on its face. These barometers were known as wheel or banjo barometers. They were invented in the late 1600s and grew to popularity in the subsequent century. These barometers still used the same principle of the stick barometer, but instead of showing the column of mercury, the wheel barometer used a pulley and counter-weights to show the amount of air pressure. These barometers were no less ornate lavishly designed as their stick counterparts.
The Mercury-less Barometer
In 1840, another type of barometer was introduced to the public: the aneroid barometer. Produced by Lucien Vidie, a Frenchman, this barometer was unlike the previous versions as it did not use mercury. It instead used a metal vacuum disc in place of the glass tube. While not as accurate as its predecessor, it nonetheless performed its desired functions. It also paved the way for the creation of the portable or pocket barometer, which much like a watch, can be carried by people wherever they go. This also made it possible to have barometers onboard ships as these are not affected by the movement of the vessel.
The Modern Barometer
Nowadays, there is such a thing as a digital barometer which uses electrical components to measure the atmospheric pressure. Some are standalone devices while others are incorporated in some other gadget such as a watch or smartphone. These types of barometers are not known to be collectables.
The Collectability of Antique Barometers
There is no question that antique barometers are highly sought after by collectors and enthusiasts. In fact, some of the older, complete and functioning pieces can cost up to $25,000. A not so old working one can start at $250. Note that working does not mean it is in pristine condition. It only means that it functions as intended. This does not mean, however, that antique barometers are hard to collect. At the peak of their popularity, there were at least 2,000 makers and retailers dealing in barometers in England alone. Some of these makers include: Negretti & Zambra, Comitti and Son, Dolland & Co., Troughton & Simms, and that is just naming a few.
Why do antique barometers cost so much?
There are at least two factors that contribute to this. First is that these devices were first made for the truly wealthy. As such, the materials and craftsmanship put into them are top-notch. Quality demands a higher price. Second is that these devices are quite fragile. Glass is a main component of the mercury barometers and they break easily. They can be replaced but if not replaced with the same type of tube from the same era, the value of the barometer would be greatly reduced. Not only the glass but the other components can be damaged or destroyed easily if not taken cared of properly. In fact, you would be hard-pressed to find a complete and functioning barometer made before 1740.
Tips for the first-time collector
You’ve decided to delve in and purchase your first antique barometer. Here are some tips to help you make your decision:
Do your research. There are several websites and books that you can peruse to make you better acquainted with what you are getting yourself into. Be informed.
Purchase the best one you can afford. Don’t go over budget. Also, know that whatever you buy, you might still have to spend some more to restore it to its original condition.
Only purchase from a reputable dealer, antique auction or an antique shop with a good reputation. Do the research. If possible, avoid purchasing from an online store unless said store is certified to be trustworthy.
Restoring Your Purchased Barometer
You’ve purchased your antique barometer and decided to restore it to its original condition. If it’s just a matter of cleaning and polishing it, then, by all means, do it yourself. If it involves more than that and you don’t know what you’re going to do, then don’t try to do it yourself. Get a specialist to do it. However, don’t just drop off your barometer and let the specialist do everything. Discuss what you want to be done to your barometer in as much detail as possible. If you’re on a budget, restoring can get expensive. Work with your specialist as to how to restore your piece in a manner that you can be happy with that is also within budget.
A Note About Mercury
In the late 1990s up to early 2000s, quite a number of countries started prohibiting the use of mercury on devices as it can be a health hazard. Before purchasing a mercury barometer, check your local and national laws as to the status of owning a device that uses mercury. Several countries have exempted barometers from the prohibition, and it is generally agreed upon that the devices pose little to no health hazard to the user, but it doesn’t hurt to be sure. If you are in a country that does ban mercury, then you can always get an aneroid barometer.