C&t Patent Altitude Adjustment Aneroid Barometer by Short & Mason, London

For sale, an early Twentieth Century brass cased aneroid with C&T patent altitude adjustment by Short & Mason Limited, London.

Comprised of a five-inch white ceramic and painted dial with scale divided for 26 – 31 degrees of barometric pressure around the entire circumference. Around the inner arc it is painted with weather indications in a beautiful Gothic font. It is further painted with the word, “aneroid barometer” to the base and with the maker’s name, “Short & Mason Ltd, London” above.

This rare form of aneroid barometer has three pointers incorporated into its design with a blue steel pointer indicating current pressure at chosen elevation and a brass pointer which allows the recording of the pressure at a given reading point.

The final pointer is constructed in copper and denotes this instrument as having been manufactured for the C&T patent altitude adjustment.

The company describes this invention in its 1911 catalogue as follows:

The C&T patent altitude adjustment consists of an auxiliary hand of copper. This is adjustably attached to the pressure hand and moves with it, While the pressure hand shows the actual atmospheric pressure at the altitude at which the aneroid is used, the copper hand may be so adjusted as to show always the corresponding sea level pressure.

For example: If an aneroid were to be used at Spokane, Washington (an altitude of 1910 feet) the copper hand would be moved away from the blue hand to the right a distance equal to 1.95” of pressure. When this hand is so attached it will always read 1.95” from the pressure hand, as they work together. This difference accounts for the altitude of the city.

This scarce sea level reading aneroid example is contained within a brass graduated case with brass bezel and bevelled glass

The makers Short & Mason were formed by Thomas Watling Short & William James Mason in 1864 and were based in Hatton Garden, London. They were makers of barometers and scientific instruments, but a significant part of their business was focused upon aneroid barometers and later barographs for which they had an unparalleled reputation by the end of the Nineteenth Century.

The partnership between the founders was dissolved at the turn of the century and the company was acquired by the US Company, Taylor Brothers who themselves had been in the business of scientific instrument making since 1851. Taylor Brothers benefited from the expertise that Short & Mason brought to the company and the instruments produced, were variously signed depending on which market the instrument was destined. In 1907, the US arm renamed itself The Taylor Instrument Company and began to use the brand name of, Tycos. This was eventually dropped in 1932 and the company reverted to the Taylor name.

Circa 1910