Edney Hair Hygrometer Joins the Collection
A rare Edney Hair Hygrometer, dating from around 1915, joins the collection alongside an expanded history of its London manufacturer, Pastorelli & Rapkin.
We are pleased to announce the addition of an Edney Hair Hygrometer, manufactured around 1915 by the renowned London scientific instrument maker Pastorelli & Rapkin Ltd.
Bearing serial number 510, this elegant instrument features a ventilated brass case, a silver-plated dial, and a distinctive blued-steel pointer. Its remarkably simple mechanism uses a tensioned bundle of natural hairs, whose length changes with atmospheric humidity, to indicate relative humidity directly on a graduated scale.
The name “Edney” was used by Pastorelli & Rapkin for an extensive range of meteorological instruments, including hygrometers, hygrographs, thermographs, and combined recording devices.
Alongside this new acquisition, we have also substantially expanded our history of Pastorelli & Rapkin, exploring the company’s origins, development, scientific instrument production, and contribution to British meteorology. The updated historical account provides further context for the firm’s instruments and its place in London’s scientific instrument-making tradition.
The new hygrometer and the expanded company history are now available to explore on Barometers Realm.