A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Lars Bergman
Date: 2017 Feb 7, 14:30 -0800
Robin and Brad,
When Worsley writes about his Epitome, I would guess it was Norie's "Epitome of Practical Navigation", including nautical tables. There were many editions but I have no idea of which one Worsley had.
Regarding the missing leading digits I do not think that Robin's explanation is correct. Worsley talks specifically on DR figures. The DR calculations were done using a traverse table during the voyage. The only time he used logs to calculate course and distance is in the entry above April 24th, when he calculates the track between Cape Belsham and a point 46 minutes of longitude west of Wallis. And on that instance he actually used leading digits.
The missing leading digits in the time sight calculations is rather from old habit, Worsley knew from long experience what the leading digit in the answer would be.
Of the discrepancies between the book and Brad's log, I can explain two of them:
4th May "run N36°E fifty-two miles" is the actual run made between observed noon position on the 3rd and observed noon position on the 4th. The transcript shows the run by DR since previous noon.
5th May "N50°E ninety-six miles" must be a mis-reading by Worsley. The transcript's 95 miles is correct and used for calculating the DR noon position from the observed position obtained on the 4th. It is clearly shown that Worsley subtracts 1°1' from the latitude and 2°7' from the longitude. For 96 miles the values should have been 1°2' and 2°8' respectively. Worsley complains somewhere in his book that he himself had great difficulties to read his own handwriting after a few month.