NavList:

Robin Stuart, you wrote:
"Worsely must have had some tables with him. "

Another issue to bear in mind: the word "epitome" was much more common and generic a hundred years ago and comparable in meaning to "guidebook" or "reference". His "epitome" might have been any number of standard references on navigation --anything with the requisite tables, which are nearly ubiquitous. This is highly standardized navigation of a type that was practiced on nearly every vessel at sea in this era. It's possible that there might be some clue in the numbers somewhere, maybe a single erroneous digit in the sixth place of a logarithm that is a 3 instead of an 8 only in Norie's epitome, but it may equally well be that there is no evidence to decide it. An epitome is a book; that much is all that is certain.

I don't think we need to force all the data into one book, one epitome, either. We can assume that the expedition had numerous printed resources. We can also assume Worsley knew how to tear pages out of books. Any traveler economizing on space knows the trick: rip out the pages you need, and burn the pages for the places you've already visited.

Frank Reed