David vincent Posted 11 May , 2020 Share Posted 11 May , 2020 Someone would know how to date this long view please ? Thanks ! Link to comment Share on other sites More sharing options...
johnboy Posted 11 May , 2020 Share Posted 11 May , 2020 Are there any markings on it? Link to comment Share on other sites More sharing options...
David vincent Posted 11 May , 2020 Author Share Posted 11 May , 2020 6 minutes ago, johnboy said: Are there any markings on it? No, there is no registration on it. Link to comment Share on other sites More sharing options...
johnboy Posted 11 May , 2020 Share Posted 11 May , 2020 Without any markings it is impossible to ID it. Is it thought to be WW1? Link to comment Share on other sites More sharing options...
303man Posted 12 May , 2020 Share Posted 12 May , 2020 The knurling looks far to crisp to be of any age, my thoughts made in india or china in the last 10 years, Link to comment Share on other sites More sharing options...
MikB Posted 12 May , 2020 Share Posted 12 May , 2020 (edited) 42 minutes ago, 303man said: The knurling looks far to crisp to be of any age, my thoughts made in india or china in the last 10 years, My thoughts too. WW1 period instruments tend to show a finer, radiused spiral knurl. That sharp, heavy parallel knurl is the first thing I noticed, and immediately thought of Indian instruments. It appears from the dismantled pic that it has a non-achromatic single-element uncoated objective, which I've also seen on Indian repros. If so it's hard to see that it could produce a quality image. Retention of the objective with a partial circlip isn't very robust either - period makers usually used a fine-threaded ring. I'm sure the Indian optics industry is capable of making excellent instruments, but those aren't what our importers buy. Edited 12 May , 2020 by MikB Link to comment Share on other sites More sharing options...
Gunner Bailey Posted 12 May , 2020 Share Posted 12 May , 2020 There's quite a tourist market in India for quality looking repro old instruments. In a hotel shop in Mumbai I found all sorts of telescopes, military compasses, sextants, all made locally and some compasses even had what looked like original dials that had been reused. All made for tourists and all worked to some extent and all were unmarked as well. Link to comment Share on other sites More sharing options...
MikB Posted 12 May , 2020 Share Posted 12 May , 2020 1 hour ago, Gunner Bailey said: There's quite a tourist market in India for quality looking repro old instruments. In a hotel shop in Mumbai I found all sorts of telescopes, military compasses, sextants, all made locally and some compasses even had what looked like original dials that had been reused. All made for tourists and all worked to some extent and all were unmarked as well. Some of the pretend prismatic compasses are abject. The prism works, but the sighting slot is usually flat against the crystal when the prism is in sighting position, instead of upright to align with the rumb line, and the alignment of lid and prism slot is random-casual - completely useless and impossible to take a valid bearing. And the example I have bears the name of Ross! As if. Link to comment Share on other sites More sharing options...
healdav Posted 13 May , 2020 Share Posted 13 May , 2020 16 hours ago, MikB said: Some of the pretend prismatic compasses are abject. The prism works, but the sighting slot is usually flat against the crystal when the prism is in sighting position, instead of upright to align with the rumb line, and the alignment of lid and prism slot is random-casual - completely useless and impossible to take a valid bearing. And the example I have bears the name of Ross! As if. I have a real one from 1917, and there is a 'hole' in the lid with a small spike to sight on. There is a very small button on the side of the compass which prevents the compass card from moving, so that you can take your eye off the target and see what the card says. It can be a bit tricky to use at first, but you get used to it. Link to comment Share on other sites More sharing options...
MikB Posted 13 May , 2020 Share Posted 13 May , 2020 7 minutes ago, healdav said: I have a real one from 1917, and there is a 'hole' in the lid with a small spike to sight on. There is a very small button on the side of the compass which prevents the compass card from moving, so that you can take your eye off the target and see what the card says. It can be a bit tricky to use at first, but you get used to it. The Verners Pattern have the button as well as a proper prism and sighting slot. The button you mention was there to damp the oscillation in that type, as the card was on a dry pivot, not in a liquid-filled cell. You sight through slot and sighting line on the (upright) lid window, keeping your finger on the button to gently reduce the swing until you can see what value the card would settle on if you gave it enough time. It can be as accurate as a liquid-filled prismatic, but you'd have to be very practiced to be as quick. Link to comment Share on other sites More sharing options...
Gunner Bailey Posted 13 May , 2020 Share Posted 13 May , 2020 I bought a compass that appeared to have a very old dial and in use it was a degree or so out compared to my modern walking compass. I knew it was repro but just liked it. Link to comment Share on other sites More sharing options...
healdav Posted 13 May , 2020 Share Posted 13 May , 2020 5 hours ago, MikB said: The Verners Pattern have the button as well as a proper prism and sighting slot. The button you mention was there to damp the oscillation in that type, as the card was on a dry pivot, not in a liquid-filled cell. You sight through slot and sighting line on the (upright) lid window, keeping your finger on the button to gently reduce the swing until you can see what value the card would settle on if you gave it enough time. It can be as accurate as a liquid-filled prismatic, but you'd have to be very practiced to be as quick. I used this one for years, including at Outward Bound School in Snowdonia, and Duke of Edinburgh's across Dartmoor. I actually got it from my father who, before the war, had belonged to a boat club, and they used it in their pulling gig. It did get getting used to, but I think that if used by an artillery officer, for example, he wouldn't be walking, and might well have some sort of stand to put it on. Link to comment Share on other sites More sharing options...
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