Some general notes about when French makers started Serial numbers

[Steven Tribe]

Unlike some UK and German (Ross and Voigtlander as the best examples) Parisian makers were apparently not very keen on giving a serial number on their brass engraving. I have looked at the following makers to see if we can deduce both when and why they introduced serial numbers.

Darlot, Jamin - Jamin/Darlot, Hermagis, Lerebours and Derogy. I have excluded Gasc et Charconnet and Auzoux et Francais/Francais as they they were all established in the 1860's and serial numbers look "artificially inflated".

Jamin has a early "Cone" lens n.172. I am not aware of the french patent info. for this design (if there is a patent date), but a guess would be 1855. The painful transfer to Darlot (Serial no. approx. 4,000) occured in 1859.

Lerebours is more difficult, as he had no patents in the 1850's. His UK agent was J.F. Shew and he started in the early 1850, but was advertising french imports in 1858. His sold Lerebours lenses were in the 6000-7000 range. But Lerebours has a recorded serial number of 2140 which probably brings him back to the middle 1840’s.

Hermagis is an easy one. He started in 1856/57 with serial numbers. All early serial numbers are on the Convertible which was patented in 1856. Like many others, he started well above 0001. Perhaps the first known, 6895, represents a realistic figure of the number Hermagis had made alone and together with Derogy and Wallet. There are quite a lot of Hermagis Petzvals which don’t have serial Numbers. Generally considered to be projection lenses, these are just pre-1856 products. Originally these had either internal washer stops or brass lens hood inserts to control depth of field.

Derogy in another one who appears to have started with a patent - multiples foyer, from 1858.
Although there is an achromat with 4175, the first noted Foyers multiples comes shortly afterwards at 4290. Again, it looks like there has been a guestimate of previous production he was associated with.

Lerebours was definitely the first, although the lack of serial Numbers before 1845 makes it impossible to give an exact date. Jamin, Hermagis and Derogy all appear in connection with their patents, but now we are in the 1850’s!