Fortin Barometer

Are you looking for a Fortin barometer? This type of barometer, which is also sometimes known as a stick barometer and a weather service barometer, has been in use for more than a century. It is essentially a metal tube that has a glass reservoir containing mercury at the bottom and a scale at the top. The Fortin barometer is highly accurate, in fact it is likely the most accurate type of barometer, and has seen long service in science classrooms, laboratories, and weather stations.  In essence it works through the action of atmospheric pressure causing the mercury level in the cistern to either rise or fall.

For the last 60 years, the industry leader manufacturing the Fortin barometer, and eventually the only company manufacturing this type of barometer, was a company called Princo Instruments. However, Princo Instruments discontinued making the Fortin barometer, and all other devices containing mercury, in the spring of 2007. Consequently, if you want to buy a Fortin barometer, you need to look online for antique barometers.  Here are a couple of examples of antique Fortin barometers I found online.

1. A U.K. site, called antiquebarometers [dot] org [dot] uk, has a range of antique Fortin barometers for sale. These include an interesting old scaled manometer / barometer, made out of boxwood by the London, U.K., firm of James Simpson & Company Ltd. This simple though curious Fortin barometer measures 35 inches long x 4 inches wide and is priced at approximately $800. The scales, which are mounted on a plain mahogany board, read pounds pressure per square inch from 5 -15 inches on the left and from 2 – 31 inches on the right, and the barometer has a large blown glass cistern resembling those of continental European barometers. It was likely made early in the 20th century.

2. The same site also features a much more elaborate American Forecast Barometer, priced at around $6400. This Fortin barometer, which was made around 1890 by the London firm Joseph Davis and Co., is a fascinating and rare variation on another barometer, known as the Polytechnic Barometer, also made by Davis.  It has an oak case containing a silver-effect painted dial. There is fretwork behind the glass front, 7-day recording dials underneath the main dial, a thermometer situated to the center of the case, and a compass inset into the base. It measures 41.5 inches x 12.5 inches and is in good condition.

With luck, these descriptions of two examples of antique Fortin barometer will have whetted your appetite to find out a bit more about the variety that is available online. There are quite a few  at different sites online, so I’d suggest you take some time to dip into the world of fine antique barometers and have a look for yourself.