Posted by Tim
on 5/30/2009, 13:42:59, in reply to "Re: young and sons transit"
74.87.13.159
Dan,
From what I can tell you have a transit with no serial number. These were produced in the 1870’s to 1880’s even though the maker did put serial numbers on some of the instruments. The patent you refer to is for an improved vernier. You mention a scale inside the compass. This is used for correcting the magnetic variation (also known as magnetic deviation. This was done to allow the compass needle to point to true north. The other scale you mentioned should go to 60 degrees wit a few extra graduations beyond that number. This was an option that Young & Sons offered. As far as dating the instrument we do know of the patent date that is mentioned so sometime after that date. Say 1876-1880 this is only an estimate.
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