Thomas Roberts working at 34 Strand Street in Liverpool, UK. A barometer with a Sympiesometer.

Thomas Roberts is recorded in Mercer, Tony Chronometer Makers of the World as working in Liverpool 1860-73. During that time, he was a Maker to the Admiralty. A number of chronometers are known bering his name.

This large marine barometer was made circa 1870. The case is mahogany and measures approximately 37 inches long, 5.5 inches wide and protrudes from the wall 3.5 inches. The bottom of the case is fitted with a decorative brass cap. Inside this is the cistern for the barometer. In the middle of the case is a large rectangular box that is fitted with a glass front. This box measures approximately 13.75 inches long and 3.75 inches wide. Behind the glass is an engraved brass plate that has been treated with a silver wash. The lower section reads, “IMPROVED SYMPIESOMETER.” The fancy Sympiesometer tube is located to the right of the thermometer inside the rectangular box. An engraved brass scale is located on the right. It is graduated from 27 to 31 and includes the following titles: Rain, Change and Fair. This is adjustable. To the left side of this space is Fahrenheit thermometer that is graded from 25 to 120 degrees. Fixed on a metal scale is a wheel that includes a small moveable dial reading from 27 to 31. Above the Sympiesometer is the brass ring for a gimbal mounting system. (The wall mount is most likely on the last boat that this fine instrument served on.) Above this ring is where you adjust the two verniers located in the upper section. This is done with a turned knob, made of shell. These are located in the upper section or main face which is also behind the glass. This is carefully lined in bone. The bone information plates are engraved with scales and their corresponding verniers. The on on the left is marked “10 A. M. YESTERDAY.” The one to the right is marked, “10 A. M. TODAY.” These scales range from 26.5 to 31. These numbers corresponds to the level of mercury in the main tube. This level can be viewed in the area between the verniers. Also engraved in the upper section is the retailer’s information. It reads “T. ROBERTS / STRAND ST” on the left side and “LIVERPOOL “ on the right. The top of this case is fitted with a decorative wooden molding.

This style of barometer is designed to be portable. Originally purchased by ships captian, it was designed to be brought with them out at sea. The gimbal hardware ensured that the instrument would remain in an upright position as the ship moved along with the waves. When at home, the captian would simply hang it on the wall and display it as it is now. The gimbal mount is currently not with this instrument. It must be on the last ship it serviced.

For more information about this clock click  here .