In November, David Rooney mentioned the Venner time switches in telephone kiosks. This prompted wheels to whir in my brain and I went hunting in my ‘reserve collection’ for something I acquired many years ago, by chance.
Unfortunately, the history of the firm as presently researched is somewhat sketchy. If anyone is interested in doing so, here is a workshop ledger from Venner, c.1934 onwards. It is a systematically arranged in-house descriptive and photographic catalogue of several hundred ‘specials’, produced from the early 1930s to the late 1940s. Every item had a unique code, all indexed, and most items have a fine quality photograph, with a scale included – these people meant business, and they were perfectionists.
Venner master clocks are finely finished, but this meticulous approach extended to machinery that would probably be invisible throughout its life. As often in the mid-twentieth century, when electro-mechanics were relied on and before integrated circuits, the requirements for accurate timing and switching, perhaps with some programming, necessitated significant mechanical and engineering ingenuity. It is telling that each description starts with ‘special’.
From 1938, we learn that the Royal Physical Society needed a system for lecturers, which would switch a green lamp to amber, one minute before time, and then to red when their allotted slot expired.
In all it is a marvellous piece of ephemera and testament to the very high standards set by manufacturers of mysterious clockwork black boxes which are worthy of closer study.