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Hello,

I am a land surveyor that is interested in surveying history. Can anyone inform me on what the smallest direct reading would have been on a sextant that would have been used in 1818? In other words late 18th and early 19th century sextants? 

Here is a sample page from Peter Fidler's journal from 1808. Fidler was a fur trader with the Hudson's Bay Company but he also used his sextant to map out everywhere that he travelled (he travelled a lot, perhaps around 35 000 to 40 000 miles by canoe and foot). Along with Philip Turnor and David Thompson, he mapped out much of what is now Canada in the late 1700s and early 1800s using a sextant. You can see from the journal entry that he read his sextant to 15" (Turnor and Thompson also never recorded a sextant reading that wasn't a multiple of 15"). 

Ken Muldrew.