Rototherm Red Bakelite Dual Scale Desk Thermometer

A mid-20th century Rototherm desktop thermometer in rare red Bakelite and with dual readings in Centigrade and Fahrenheit. Second-hand.

Availability: Out of stock.

Stock ID: 1756

A rare Rototherm red Bakelite, dual-scale desktop thermometer for sale

This is a vintage, second-hand, mid-20th century Rototherm desktop thermometer cast in red Bakelite, which is among the rarest colours in which you will find these thermometers.

It is a bimetallic thermometer, made by the British scientific instrument manufacturer Rototherm. In addition to the colour, it is a also a bit rarer because it gives dual readings in Centigrade and Fahrenheit.

It has an off-white dial and a black needle providing measurements in degrees Celsius on the red scale, and in degrees Fahrenheit on the black.

The arrowed mark at 16°C (61°F) denotes the 'minimum working temperature for sitting workers', from the British Factory Act of 1961. Typically, it was just for guidance and not for strict enforcement. (Thanks to Ian for the info).

It seems to be fairly accurate as is, but it can always be calibrated by removing the rear panel and gently twisting the back of the needle assembly.

Bakelite has become a generic description for items made of early plastics and resins, like Lucite, Catalin, Galalith, Bakelite and urea-formaldehyde resin. The Rototherm thermometers were apparently made from urea-formaldehyde.

A British-made, mid-20th century Rototherm thermometer

It was made in England by Rototherm. They invented the bi-metallic thermometer and the patent is showing as "Registered" on the dial. This example was probably made in the 1930s or 1940s.