Antique Edney thermograph from the late 19th century made by John Kirkaldy Ltd, London. An Edney thermograph is a recording thermometer used to measure and record the temperature over a specific period. It uses a bimetallic strip which contracts and expands with the temperature shifts. Via a mechanism with a long lever and a pen the temperature is written on rotating diagram paper.

The John Kirkaldy company was founded in 1809, it registered as John Kirkaldy Ltd. in 1887 after the death of the founder John Given Kirkaldy. The company was well-known for producing marine and industrial instruments, like f.e. the Compactum fresh distiller which converts seawater into drinkable fresh water. The company was active until the late 1920's.

Our thermograph is in a good condition. The internal mechanism to rotate the paper diagram is still functional, you can wind it on top. The bimetallic strip and lever all seem ok. Only the pen at the end of the lever is missing. The serial number of the instrument is 570, which dates it around 1890-1900.

The outer case is made of copper with brass, the lid is a bit loose. There are 2 screws missing at the point where it hinges. The bottom is made of cast iron. The case has some patina and some light wear and tear, but nothing serious.

Take a good look at the photos for a good impression.

The dimensions of the thermograph are 28 x 14 x 19 cm and the weight is 4 kgs.