Antique pocket barometer with 1¼” engraved and silvered dial having a barometric range from 24 – 31 inches of mercury, equivalent altimetric range 0 – 6,000ft, the centre signed by the maker “C.W. Dixey, 3 New Bond Street, London.” Fine blued steel pointer. Rotating bezel with index to reflector ring, the bevelled glass a replacement.

Single ¾” capsule driven, colour case hardened  movement of unusual design and execution, tensioned on a coil spring; most major steel components struck with the serial no. “66,” Hair spring mounted above the cock. The steel chassis maintained on a silver back plate with three screws and a further three levelling screws.

All contained within a finely rose engine turned, drum form silver case with extension and suspension loop. The verso rotated about a central blued steel screw to reveal the calibration square.

Together with its original leather over wood, brown velvet lined case, the inner lid with printed paper conversion table equating inches of mercury to altitude. Snap closure on a button release. Later adjustment key.

This is one of the most interesting instruments of its type we have ever examined. Undeniably very early in the evolutionary time scale of pocket barometers, placing it within the first two or three years of these instruments first appearing, perhaps one of the very first – there is very good evidence to suggest just that as the entire instrument has a strong suggestion of early making.

When these devices first appeared all makers had to start from scratch. Although the many aspects involved in the making of the components were everyday skills, the mechanism itself was, of course, entirely new. The almost immediate and insatiable demand for these pieces caused rapid expansion in the firms that set up to produce them. Many of these companies were existing makers of other scientific products which meant the hiring of more craftsmen to make barometers.

The movement in this barometer was almost certainly made by someone who had experience as a lock maker in the gun trade. We have seen colour case hardening on a few movements before, notably by Browning – never though a combination of case hardening and the serial numbering of all the major components. This combination suggests movements built up and finished, then disassembled, numbered and heated in a fire with ground-up bone meal and old leather to achieve the decoration we now see. It is something of a shame that the original owner of this wonderful piece probably never had the chance to view the craftsmanship that lay below the dial.

There are aspects of the design of this movement that make it very unusual indeed: the setting of the hair spring above the cock which is double pinned with two blued steel screws; the termination of the amplification lever; and the provision of levelling screws to ensure the pointer rotates in the same plane as the dial. Additionally, the calibration screw terminates in a square and not the almost universal slotted screw.

Instruments such as this that survive are very few indeed, the numbers produced originally being very modest , often not exceeding a few hundred or even less.

Having been inspected, serviced and calibrated, it is offered in good working order and condition. Some minor marks to the dial, the silver case clean and crisp, minor marks to circumference. The leather case generally worn, evidence of small repair to area of keeper, some looseness in the hinge but serviceable. The paper conversion chart aged, stained with some losses.

Charles Wastell Dixey is recorded as working from 3 New Bond Street, London from 1838 onwards. During the course of 1863, the firm name changed to C.W. Dixey & Son when his son Adolphus joined in partnership. The firm of C.W. Dixey & Son still trades today.

Dimensions: 1⅝” diameter x ¾” deep

Stock No: PB0832

Price: Vavasseur Archive