View Full Version : Deciphering a Darlot lens date

Jim C.
18-Sep-2013, 21:35
I was cleaning up a recent lens purchase and I'm wondering what a different set of eyes
sees in this date written on the lens by Geo H Walker, who I guess assembled the lens.
I'm seeing Aprile 26 197511, not sure what the extra 1's are supposed to mean.


There also a word after Monsieur Walkers name, could a forum member
who's more fluent with French possibly translate that ?


Steven Tribe
19-Sep-2013, 00:56
Is there a serial number on the lens?

The limited experience I have with Darlot's text on GG lens edges is that they are not as straightforward as Hermagis (see the current running thread on this!).

There is another problem in that glued achromats have a finite life and, in my rebalsaming of 19th century achromats, I have have found many that have already been redone at least once before! The original markings are quite resistant to removal but do suffer damage. Additionally, the lens repairer may have added his own "workshop" identification in the same way that watch and clock repairers have done for centuries.

Somehow, I think it is unlikely that there was someone called "Walker" employed at Darlot's lens workshop.

I enclose a photo of another Darlot (24,842) which shows the traces of the original markings after a repair during its 149 year life. This has the "washed out" markings from Darlot Paris and an additional number "701" written upsidedown - perhaps by the repairer?

Steven Tribe
19-Sep-2013, 04:47
By the way, Aprile is not the French word for the month of April!

Jim C.
19-Sep-2013, 07:52
There is a serial number on the lens, 27,604, the barrel is marked Darlot Opticien Paris.

If I read the date as 1875 the VM alludes it to a portrait lens, with a 7 in focal length,
I checked it and I measured about 7.5", cross referencing with Dan's 1890 catalog made me unsure,
the barrel is 2.70" diameter and the closest diameter the catalog lists portrait lenses is 2.25", and 3" for
waterhouse stopped rack and pinion lens and 2.5" and 3" for quick working lenses.
The date writing is on the rear air spaced elements, the front element just has " 3 Darlot glace <?> "


Looking at the 'April' more closely it does seem to be actually Avril. :o

Emmanuel BIGLER
19-Sep-2013, 08:06
Hello from France (my post just apperaed after Jim's last post, so eventually our conclusions are very similar)
Althought French is my mother tongue, it is hard to decipher what is written.

On image # IMG_1998_2.jpg, the 1st word could possibly be "Walker" The next word is hard to read and start as "altern..." then the 2 letters Z and U.
"Walker" in itself is a puzzle since this definitely sounds like a British name, it is not at all a French patronym nor a French christian name. Walter does exits but is more a German name.

On image # IMG_2001.jpg, the first word could be AVRIL which is the name in French for the month of April.
However if the text is French, by no way it can be a date since in a French style for date, the sequence of words is very different from the English style.
For example, "18 avril 1826" would be the correct way to write April 18, 1826. So in France AVRIL 26 cannot be a date if the date is written in French.

hence I have no clue. could be AVRIL. Then for sure 2 6 and 1 ? 8 ? 7 5 11

The 2nd digit in the last series looks like a "9" but if it were an un-finished "8" this would read "1875" I'm not a Darlot specialist, hence those who know will be able to tel us whether 1875 is anachronic or not.

The last image clearly (well, after playing with the contrast curves displaying the jpeg) shows "Darlot Paris" with a nice hand-written P like in the good old days (I learned to write like this).

A difficult deciphering task !! Sometimes people used abbreviations that are no longer in use today. Hence the "altern ..." word could be an abbreviation of something...

Steven Tribe
19-Sep-2013, 08:41
Serial number 27,604 is only a couple of 1000 (at most) after Darlot gave up the reference to Jamin in the engraving. This was around 1864, so yours is 1865/66.
Note that Darlot appears to have started another series of serial numbers around this time for other lens designs (Universel, Hemispherique).

Jim C.
19-Sep-2013, 10:26
Emmanuel - Thanks ! I would have never guessed that what I thought was "Glace" would be Paris !
The Geo H Walker I was able to read pretty clearly, I searched for his name and wound up with a
George Herbert Walker, related to ex president Bush ! I don't think it's the same guy, but it would be funny
if it was and once owned the lens.

Steven also surmised as did I, that Walker probably wasn't assembling lenses in France at that time.

The date sequence is still a riddle, I had forgot that the rest of the world except the US uses the Day, Month, Year sequence.
I did the same thing of assuming that the "9" was a unfinished "8", too bad there was nothing else written in numbers on the
lenses to see if the handwriting style could be compared to.

Steven - Thanks for pinpointing the date, it's a little earlier than I guessed.