WW1 'Periscope Prism company' sniper scope???

[Surpmil]

Fellow forum member Bindi2 has asked me to post pictures of his Aldis scope in here, along with the scope rings he has. I have already told him these scope rings are Evans scope rings. The focal adjustment of his Aldis scope is something I've never seen before, maybe someone else has?

PS: Rob, finally someone dared to say this! I'll however let others speak on it..

Edit: forgot to address this today:

This is GREAT information. IF PPCo also marked the SMLE overbore mount somewhere with their name, it would make it nearly impossible that PPCo also mounted the Aldis scopes to the "PPCo dovetail" mount and NOT put their name on it anywhere. The plot thickens.. And Roger, if you find any picture of this, please do share it. That would be great to see, thanks!

I would say the drum on that scope is a post-war replacement, and that the focus adjustment cover is also. Whoever did it has gone to the effort of scavenging a portion of another Aldis sight (artillery type) and adapting that to fit with a replacement knurled screw. There was certainly no need for Aldis to add their name on that part, nor to make it so massively heavy, nor to change the pattern we have documented before and after this scope in serial number. The scopes that were re-used in Australia seem to have had long, hard lives to judge by the state of the finish on them (used to have one such myself). I suspect this is another example of that. To wear off that very durable black baked-enamel on the ocular housings is the work of years of steady use!

I suggest an Aldis sight similar to this was the "donor" - most of these relatively useless artillery sights were broken up for scrap and lenses post-war after all.

Taking this line of thought a little further........if you look at the contract details (post number 65) - the entry dated 30/09/16 refers to a contract placed with Aldis Brothers to 'Fit Telescopic sights with Bartle fittings'. The contract size is 700. There is a second similar entry dated 18/10/16 for a further 700 units. So, if the 'modified PPCo rings' & the 'Bartle fittings' are one & the same, it would explain why the scopes turn up reasonably frequently.....
Immediately above the second entry is a further reference to Aldis for a contract for 2254 'sights telescopic' but with no further qualification. Although above the 18/10/16 entry, it is dated two days later.

Further, if the fitting of Aldis scopes using mounts supplied by J Bartle was carried out by Aldis Brothers themselves, they (Aldis) didn't really need to put their company name all over the rings, as it was already boldly emblazoned on the ocular lens housing. To add it again may have been seen therefore as unnecessary.

Terribly difficult to prove or disprove, but it seems very plausible. I wonder if there are still patent details extant for a J Bartle telescopic sight mount.....or if produced by Bartle at the behest of PPCo or the government, & as it is the same in principle, would it have been covered by PPCo's original patent of February 1915? Just thinking aloud....

It sounds very plausible and as per my previous, if the patents on the PPCo. mount were an asset of the company rather than the property of an inventor (in or out of the firm), which they licensed, then they no doubt went with the company when taken over and thus the ministry could do what it liked with them. Unfortunately UK historical patents are all over the place it seems and not accessible online, so some curious person will have to go to the British Library and rummage through the dusty ledgers!

Yes muffet - a good point. I think there is a lot of new evidence trickling from some excellent collections, and a fair bit of thinking out loud. Once this thread has exhausted, the best points and photos could probably generate a new book....ATB, D.

Or at least an updated edition of a previously published book!

....
Regarding surpmil's point about PPCo company ownership, I remain confused as anyone. Who were the shareholders? A bunch of private citizens or the Govt? Are they talking takeover of ownership or just management? If the Govt owned PPCo, when was the take-over? If Govt owned, then I can accept the idea that PPCo made dovetail mounts might have omitted the patent acknowledgement and company name if they wanted to. Maybe as a company in crisis under wartime pressures, details like this slipped between the cracks? On some of the 1918 /1919 overbore scopes they made efforts to mark the scopes, and on others, they do not. Curse your inconsistency PPCo!!

PPCo. was clearly a private venture to begin as it was taken over for non-performance during the war, and had it been a government venture need not have been taken over. As for the shareholders, that info and more may be somewhere in the UK yet, but one would need to be "on the ground" there to do the research. I found no trace of them in either of the two publications of the British Scientific Instrument Makers Assocation that I have, nor in an online newspaper archive. The buildlng in Kentish Town where their offices were was torn down in the 1980s IIRC. A decade or two ago, I would have said go and ask around the area and you will probably turn up some old person who knew about the business, but very unlikely now. Best bet is track down the directors through a registry of companies that must exist somewhere in a UK archive and look for their descendants and see if they have anything in the family trunks, so to speak.

Roger, your theory about Aldis fitting the dovetail mounts does sound feasible, but patent acknowledgement could be even more desirable when mix and matching Aldis and PPCo products, especially from PPCo's point of view if PPCo actually owned the mounts patent. Would they also be paying royalties for the German scope patents?

Do you mean for the windage adjustment system? I doubt it was patented as similar methods were common on theodolites before and after WWI. As for the rest of the scope, nothing patentable there AFAIK.

So who is this Bartle character? Is it possible that PPC only "designed" the scopes, and used a Bartle design for the mounts from the outset? Getting the patent details would be interesting, to see whether it is entirely credited to PPCo, or whether Bartle's name crops up as the designer. That would make sense if Bartle was then able to collaborate with Aldis for the contract.

Could be almost anyone, but probably either an engineer at PPCo. or Aldis or somewhere within the Ministry (of Munitions?) who proposed the adaptation of the PPCo. mounts to the Aldis scopes?

I find it more curious where the prism concept itself originated, though probably it was nothing new optically.

The timing and size of the Aldis scope contracts is also a thing to consider, especially as it is so late in 1916. My own under-populated spreadsheet and rounding to the nearest hundred or so, you could get something like this:
66000 to 67500 made in 1915. Mainly No.1 and No.2 scopes
67500 to 70600 made in 1916 - Mainly No.3 scopes with a couple of No.2s at the beginning and a No.4 near the end.
70600 to 71600 made in 1916 - Almost all No.4 scopes with a couple of No.3s mixed in.

So in 1916, Aldis had made roughly 3000 No.3 scopes, plus another 1000 No.4 scopes, and I have not seen any Aldis sniper scope dated later than 1916. If the 18/10/16 order was for sniper optics, then they would have had to fit a lot of production into two months. PPCo also made optics for other guns as well, so maybe the 2254 scopes in this order were not sniper optics?

I'm updating my copy of the last spreadsheet now - is this one you got from ValleySniper also? We should blend the two of them at some point perhaps; and agree on the criteria to be recorded? I'll PM you about that.
The earliest No4 Aldis I have is around 70,000 and as you know at around 72,000 they changed the numbering system to begin at 100,000. Then, from what I have so far, it looks like they jumped it again, but need more data to confirm that.

The other thing is that almost all No.4 scopes produced have the lateral adjustment prism fitted, implying fitting in a non-windage adjustable mount. Most of the No.4 scopes in my spreadsheet are fitted with the "PPCo" (Bartle??) dovetail mount from earliest noted scope serial 70889 onwards, but with Roger's possible overbore scope in that serial rage. Starting to make sense?

The only two scopes actually fitted with the overbore claw mounts I have seen are 1916 dated No.3s serials 70501 and 70533. I am not sure what can be read into those numbers. Possibly just that the next handfuls of scopes for the overbore job were sitting on the same section of storage shelf?

Brains are dribbling out of my ears now, must go.

ATB, D

I would not be surprised if the closeness of those two numbers indicates a trial batch. I must see if I can find the photos of 70493 to compare with.

Stephen Sambrook and his contributors have already done a lot of the heavy lifting, so check the credits and bibliography if anyone has a mind to dig further!