A hundred and forty years ago there was a man in Verdun called P. Chenevier. I bet you didn’t know that… but now you do, and so do I, because he left us a little memento.
Of course, he never meant “Memento” in the common English sense; it was simply a memory aid, what today we’d call a pocket reference. He published it in 1884; and he evidently manufactured and sold it himself, because the cover gives the address as “Verdun, Meuse — Chez l’auteur” (can you imagine the Windows CD-ROM stating “Seattle, WA — Chez Bill”? )
The “Memento Graphique du Constructeur” is an unusual cardboard device about 20x7x1 cm in size, formed like a 4-page booklet with two flaps (the “covers”) opening from a central compartment that contains a removable cardboard plate with two more pages on its two faces. My first impression when I sighted this one at an antique shop in the US was that this is not a slide rule: I figured that the central plate is merely stored inside and has to be pulled out to be consulted. Years later, however, I found that the intent is for the edge of the compartment to help read out vertically aligned scales on the inner plate as it comes out, similar to a cursor hairline in a real slide rule.
The six pages are crammed with numerous graphs and tables, all related to the design of construction elements: strength of various wood and metal beams, weights of roofing plates, and so forth… all very handy for the the target population noted on the cover: “A l’usage des ingenieurs, architectes, directeurs de travaux, chefs d’usines et entrepreneurs”.
After some sleuthing I uncovered the identity of the enterprising Monsieur Chenevier. He was, it turns out, Paul-Nicolas Chenevier (1848-1923), an architect born in Paris and active in Verdun and its vicinity.
Exhibit provenance:
I found this, marked noncommittally as an “old French calculator”, in an antique mall in California.
More info:
Here is an interesting report on this device in the Bulletin of the Société d’Encouragement pour l’Industrie Nationale from November of 1884.
My more detailed article on the Memento Graphique can be found in the UKSRC Gazette, Issue 24 (Autumn 2024), Pg 128.