A very unusual larger sized aneroid pocket barometer compendium comprising barometer, altimeter and thermometer by Parkinson & Frodsham no. 270, c1880

Pocket barometer having 2⅝” silvered and die struck stepped dial, the outer bezel set altimetric non-linear scale calibrated in feet with a range from 0 – 6,000ft divided down to 50ft, the inner barometric scale calibrated in inches of mercury with a range from 25” – 31” being divided to 1/20”. The inset having standard meteorological terms, the upper part signed by the maker “Parkinson & Frodsham” and “4 Change Alley,” the lower “Cornhill, London” and “Compensated.” The dial verso struck “270.” Semi-circular thermometer, the register calibrated in degrees Fahrenheit, with a range from 20° – 120° divided to 2°. Blued steel pointer, bevelled glass.

The very unusual high quality movement of basic Vidie pattern driven from a single 1¾” nickel alloy capsule, tensioned on a C spring, finely finished cock, arbor and chain. All contained within a deep drum form lacquered brass case, pendant and bow, calibration port to verso.

Presented in its original burgundy leather over timber, purple silk and velvet lined travel case, snap closure on a button release.

Condition: The subject of a full service, conservation, and calibration under laboratory conditions, see performance chart from dynamic test. The movement working well with good sensitivity, accurate to within 0.15” across the range 25 – 31”.

The dial about perfect, the brass case retaining much original gilt lacquer finish, some oxidation, wear and light abrasions. The leather case with good colour though somewhat diminished from original, the fabric interior with further signs of UV deterioration particularly the lid silk. Structurally sound, the catch working perfectly.

Comments: This is an extremely unusual instrument. With so many of these barometers being white labelled. it is tempting to to think that this may be one such. However the construction and final finishing of the movement, clearly to a standard surpassing other contemporaries, might suggest otherwise and at this time we are happy to attribute this work, or at least the finishing and setting up, to Parkinson & Frodsham who are better known as chronometer makers.

Owing to the extreme scarcity of such Parkinson & Frodsham instruments, it is likely that a foray into barometer making was brief. The serial number “270” was found engraved onto the back of the dial – it is likely therefore that this is the instrument number.