Needle moves when tapped on counter. And you get what is left of the case. The item “Antq Compensated Pocket Barometer Altimeter bonschur & Holmes phila Tycos” is in sale since Wednesday, January 10, 2018. This item is in the category “Antiques\Science & Medicine (Pre-1930)\Scientific Instruments\Barometers”. The seller is “lamarsjunk” and is located in East Earl, Pennsylvania. This item can be shipped to United States.

• Maker: TYCOS
• Original/Reproduction: Original

This antique barometer is in a well-used brass case with a beveled glass face and brass loop for hanging. It measures 4 ¾ inches in diameter by 2 1/8 deep and is similar to one in the Smithsonian National Museum of American History collection. They state that theirs was donated by the U. Signal Corps in 1923. It is thought to have been an item found in light stations of the late nineteenth century. Barometers like this are sought by nautical instrument collectors, among others. On the back center is the logo of Naudet & Cie. HBPN, which probably stands for Holosteric Barometer Paul Naudet or possibly PHBN for. The firm began making the barometers in 1860 but the logo was registered in 1884, helping us to guess the earliest date of the instrument here. Holosteric means the same as aneroid and signifies that the instrument. Measures atmospheric pressure mechanically, without the use of fluids, by means of an evacuated hollow metallic diaphragm. It has two hands, one (brass) that can be moved by the button outside on the center of the glass to establish a current. Pressure and compare the change by the other (blue/black). You will set the brass hand based on the pressure at your location on the day you begin its use. The hand moves only slightly most of the time. On the metallic faceplate it reads Made in France and the retail company it was made for, the still existing Wall & Ochs, Philadelphia. The gradations are 25 to 31 inches (representing the mercury used in earlier barometers) and intermediate numbers from 1 to nine representing millibars. The item “Rare 19th c. Naudet Holosteric Barometer, made in Paris for Wall & Ochs, Phila” is in sale since Monday, November 09, 2015. This item is in the category “Antiques\Maritime\Other Maritime Antiques”. The seller is “lwbfla” and is located in Sarasota, Florida. This item can be shipped to United States.

• Maker: Naudet & Companie
• Primary Material: brass