trained_simian Posted 27 April , 2019 Share Posted 27 April , 2019 I purchased a telescope from an antiques fair in Peterborough a week ago. The zoom/focus mechanism is completely seized, which obscures most of the engraved identifying data. What I can make out is the following: --- Scope X 8 2341 (I think it's the serial number, as other parts are stamped with it) E & Co Ridge 18 18 --- It had a large, white rubber eyepiece on it when I bought it, but it was so fragile I carefully removed it. My intent is to mount it on a plaque for an Army Officer's farewell gift, but I'd love to know more about it and maybe fix the mechanism. The glass all appears good. I don't see a cross hairs or anything on the glass. Link to comment Share on other sites More sharing options...
MikB Posted 27 April , 2019 Share Posted 27 April , 2019 I don't know this type well at all, and suspect there's quite a bit of writing you can't see because the inner draw's seized. One of the '18's, possibly the lower one, may be the tail end of year of issue 1918. I've sometimes seen these described as naval sighting scopes - I'd guess for locally-controlled guns of maybe 4" calibre or thereabouts. If you find a Broad Arrow, an 'N' somewhere near it would denote naval issue. Link to comment Share on other sites More sharing options...
trained_simian Posted 27 April , 2019 Author Share Posted 27 April , 2019 Do you think I could disassemble it to get at the mechanism? Link to comment Share on other sites More sharing options...
MikB Posted 27 April , 2019 Share Posted 27 April , 2019 If you do, note carefully how it went together, and any obvious existing damage. It's clear from the pics that somebody with some sort of vice wrench and ill-fitting screwdriver got there before you... Link to comment Share on other sites More sharing options...
trained_simian Posted 27 April , 2019 Author Share Posted 27 April , 2019 Yeah, somebody definitely went at it with something. I can't imagine there's any coatings on the glass that would be damaged by penetrating oil? My thought is to soak it in penetrating oil, clean it off, get a soft-jawed wrench or a strap or something, put the other side in my wood vice, and see what I can do. Link to comment Share on other sites More sharing options...
Gunner Hall Posted 29 April , 2019 Share Posted 29 April , 2019 It looks to me like a direct fire sight, There were specially made to suit each type of gun. BTW, there is a similar one for sale at https://www.theauctioncentre.co.uk/catalog/?auction=298&lot=0217 If you look through it, there should be a "reticle" or sight hairs visible through the lens. Sometimes these include an engraving stating the calibre of gun it was meant for.. Years ago, there was an "Armstrong Gun" displayed at Bamburgh Castle with a similar telescope jammed in the sight mount. When you looked through it, you could see that the scope was calibrated for a 17pdr Anti Tank Gun. of 1944 vintage. Link to comment Share on other sites More sharing options...
trained_simian Posted 29 April , 2019 Author Share Posted 29 April , 2019 Thanks for that. I managed to get it unstuck. GS telescope X 8 No 2341 W.G. PYE & Co Cambridge 1918 NP18 It's missing the reticle glass at the front, for sure. The focus mechanism now turns, but has no effect. I wonder if replacing that glass is even possible these days. Link to comment Share on other sites More sharing options...
Gunner Hall Posted 29 April , 2019 Share Posted 29 April , 2019 I'm glad you managed to unstick the thing withut causing further damage. W. G Pye of Cambridge are the same mob that made transistor radios for years. They even have a Pye Museum! http://www.pyemuseum.org/divisions/history/history_pt1.php Mentions that they were involved in the manufacture of " telescopes, ALDIS lamps, gun-sights and surveying equipment" , during the Great War. The NP18 engraving made me think it was part of the 18pdr gunsight. However, google searching for this lead me to this - its a diagram of the 18pdr "Rocking Bar Sight" The telescope element of this was common across all natures that used rocking bar sights. BTW, It looks as though your piece is missing the eyepiece - Where the reticle would be set. Link to comment Share on other sites More sharing options...
trained_simian Posted 29 April , 2019 Author Share Posted 29 April , 2019 When I bought it there was a rubber eyepiece, which I carefully removed and set aside. It's obviously not in any kind of condition for use. The glass eyepiece appears to be intact. There appears to be a slot at the front of the telescope with what looks like a wire retainer spring. I presume the magnification lens would've gone there? I can't notice any other things that are missing, but I don't know what I don't know. I emailed the pye museum website, and will see if they can do anything for me. Link to comment Share on other sites More sharing options...
trained_simian Posted 29 April , 2019 Author Share Posted 29 April , 2019 Here we go. https://collections.rmg.co.uk/collections/objects/43844.html That appears to be exactly the same thing. It's a pity there isn't more listed about it there. But it's a start. Link to comment Share on other sites More sharing options...
MikB Posted 29 April , 2019 Share Posted 29 April , 2019 The 'NP' is actually 'NPL' for National Physical Laboratory - it's an inspection release mark from them, with the 2-digit year. I'd think the reticule would probably go in front of the erector cell, wherever that is in this type. The usual design for a terrestrial achromatic is a 2-element objective (biconvex and plano-concave in close contact), then a 2 lens erector cell, then a 2 lens eyepiece cell. Link to comment Share on other sites More sharing options...
trained_simian Posted 29 April , 2019 Author Share Posted 29 April , 2019 I'm not much good with optics, aside from knowing if I like the look of them or not. I'll take some pictures once I'm home, would you be able to tell me what you think is missing? Link to comment Share on other sites More sharing options...
trained_simian Posted 29 April , 2019 Author Share Posted 29 April , 2019 (edited) Edited 29 April , 2019 by trained_simian Link to comment Share on other sites More sharing options...
trained_simian Posted 29 April , 2019 Author Share Posted 29 April , 2019 I'm counting 3 pieces of glass so far. Eyepiece and 2 bits in the removable black part. Link to comment Share on other sites More sharing options...
MikB Posted 29 April , 2019 Share Posted 29 April , 2019 1 hour ago, trained_simian said: I'm not much good with optics, aside from knowing if I like the look of them or not. I'll take some pictures once I'm home, would you be able to tell me what you think is missing? I've never had one of these to bits, so I don't know how they're constructed, but I think you've a serious problem in that there's no main objective lens doublet held in by the threaded ring at the front end in your top pic. I'm guessing the 2nd pic shows the whole focussing assembly with the erector cell at the left-hand end, and in the 3rd pic you've unscrewed the erector field lens and the cell mounting flange from the focussing tube, and the flange carries the other erector lens. I'd expect two separate lenses in the eyepiece as well, but can't tell if that's what you have. And I'm wondering if the 4 blobs I can see on what might be the front end of the eyepiece cell are where the crosswire reticule once attached. The big focussing sleeve with the helical track on it moves the whole assembly to and fro in relation to the objective. Link to comment Share on other sites More sharing options...
trained_simian Posted 29 April , 2019 Author Share Posted 29 April , 2019 NUpon closer inspection, there's definitely 2 lenses in the eyepiece assembly. So that makes 4 total. Crosswire reticle: you're right. The screws look like they clamp down a cruciform wire. There's notches by each one. And the lens, yeah... Obviously I can't just toss a piece of glass in there, but if I know the end result should be 8x magnification, would I be able to take this thing to a shop that might be able to source an appropriate lens? Link to comment Share on other sites More sharing options...
MikB Posted 29 April , 2019 Share Posted 29 April , 2019 Magnification is normally a function of the eyepiece only - for example, the signalling telescope series Tel. Sig. Mk. I - VI have separate low (15x) and high (30x) eyepiece cells but the erector and objective elements remain unchanged. So possibly the objective of any of the sighting telescope series of the same length and diameter as yours might do the job, but I don't know how you'd calculate the lens profile from scratch. Bear in mid that it'll be a doublet. I've not used this outfit:- http://www.actionoptics.co.uk/ ...but I've read good reports of them. Don't know whether they might have a bits box they could raid for you. Link to comment Share on other sites More sharing options...
trained_simian Posted 29 April , 2019 Author Share Posted 29 April , 2019 I'll send them an email and see what they say. Ultimately this scope is going to a desk ornament, but I'd love to get it functional again. Link to comment Share on other sites More sharing options...
Ironblood Posted 2 March , 2023 Share Posted 2 March , 2023 (edited) I have a small collection of Admiralty Pattern lenses with different stock codes pertaining to different mile-to-inch ratios. ("4 miles to 1 inch - [20 inch circle]") and so on. (A.P. Nos. 781, 785, 786, 787, 789 & 791). All have clear transparent glass in a thick brass 55mm diameter frame with machine-etched markings Some came with their own envelope-grade square brown paper pouches bearing a (British Military Component) Code No. 22-53. The latter digits 53 might be a date, although this is not always the case. Does anyone here know their proper origin and purpose? Thanks Edited 2 March , 2023 by Ironblood Link to comment Share on other sites More sharing options...
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