I just bought a 1923 Gurley transit and tripod this morning. At first I thought that it had some steel parts but after looking it over it's solid brass which is nice. Anyway it looks to be in good condition but the 2 big adjuster knobs on the right side do not want to move. I don't want to force them so I thought I would post it here to hopefully get some advise on what to do. Shouldn't they move freely? Thanks in advance.
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Y level not a transit
Yea I figured that out. I emailed Gurley and got my answer. I guess these harden up over time. I will take it apart and lube it. I will get it working again.
I stand corrected, John. Thanks.
Looks like a beautiful display piece at it's 100th birthday.
Do you mind sharing how much you paid for it?
Q tip and kerosene.
Dad used to clean his Monroe calculator moving parts with it. It'll soften and dissolve old oil and grease.
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@notsomuch I got it for $50. I have completely disassembled it, Lube it, replace the crosshairs and it now works perfect. I think I am going to replace the crosshairs again. I used my own hair and it looks a bit big. I am going to try spider web. I think it will look better when focused. These pics are after all the work was done. Even though the sun glare shield is brass it looks rusted. I think that the paint that was on it had some iron additive in it.
The "rust" and discoloration on the sun-screen probably came from the salt on the operator's hands. That's pretty common on brass tools for the areas that were touched often to be somewhat corroded, off-colored and worn.
I would consider it "patina". 😉
For crosshairs, you could try taking a polyester sewing thread and unraveling one thin strand out of it. Not sure how smooth it would be but probably thinner than human hair.
For crosshairs, you could try taking a polyester sewing thread and unraveling one thin strand out of it. Not sure how smooth it would be but probably thinner than human hair.
I think that would be curly and hard to straighten. I am going to try Spider Web first. It is what they used back in the day. I guess brown recluse spider web was considered to be the best . I will say the optics are pretty clear. I can read the small signs on the hospital a half mile from my house.
I thought it was black widow spider silk that was in highest regard.
I am going to try spider web
As I recall, the spider web gets dusted with lampblack to provide contrast. (I've never replaced any crosshairs, I'm just repeating something I read somewhere.)
Edit: I just did a search on spider silk crosshairs and lampblack and found nothing, so I must have misremembered.
Interesting article on black-widow spider silk for crosshairs here: https://owlcation.com/stem/The-patriotic-black-widow-spiders-of-World-War-II No mention of lamp black…
BTW, Black-widow spiders are under threat from brown-widow spiders see:
I thought it was black widow spider silk that was in highest regard.
According to Wakopedia it's Brown Recluse web that's strong and was used in surveying . From that page
(Surveying and astronomy
In older instruments, reticle crosshairs and stadia marks were made using threads taken from the cocoon of the brown recluse spider. This very fine, strong spider silk makes for an excellent crosshair. )
https://en.wikipedia.org/wiki/Reticle
