NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Brad Morris
Date: 2013 Feb 21, 18:11 -0500
Hi Hewitt
You are discovering the same things George & I did when we investigated Worsley's log of his famous journey with Shakleton from Elephant Island to South Georgia Island.
1) Penmanship didn't count. They were scribbling down a computation for themselves, not posterity.
2) You must backward fit the numbers. If the arithmetic doesn't line up with your transcription of the log, change your transcription. Its unlikely that the navigator made an arithmetic error. More likely you read the number wrong.
3) The writing styles of numbers is very author dependent. 4's and 9's can look very much the same. 1's and 7's, etc. As long as the author knew the number, he was set.
4) The style of recording may be consistent (or not!). It looks like this navigator used columns, recording each one below the previous. Actually, this is lucky, I have read that many of these types of computations were done in chalk on a slate.
5) Sometimes, its just not going to make sense, with too many jumbled numbers. You'll have to blow each character up and compare it to "known" samples in other parts of the log. This can be very tedious and time consuming.
George & I spent hours and hours on that transcription. It was worth it because of the historical context of the log.
Regards
Brad
Frank, this is slow going for me. I'm not at all quick or comfortable with time sights. Nor have I had my second cuppa. :-) Anyway, a question: In the lower left of the upper left quadrant, the number "18 36" looks like an angle (18* 36') and the "19" under the "36" to be (19'). Then should't the addition (if it is an addition) result in 18* 55', not "18 45" ? Hewitt Sent from my iPad On Feb 21, 2013, at 9:11 AM, "Frank Reed" wrote: > Lars, you wrote: > "It is a 9 am sight of sun, lower limb, height of eye 17 feet. > December 27th, 1871 at GMT 11h51m55s civil time. > Latitude 36d37m north, longitude 42d38m west. > Chronometer 3m52s fast on GMT. > The nautical table used did not contain log sine square half angle." > > Nice! I only got a few of the details before I set it aside. How confident are you in the year of the observations? There is no other data here except another sheet of scrap paper, probably from the same voyage, with about sixty more time sights. Would anyone like to see those? > > -FER > > > ---------------------------------------------------------------- > NavList message boards and member settings: www.fer3.com/NavList > Members may optionally receive posts by email. > To cancel email delivery, send a message to NoMail[at]fer3.com > ---------------------------------------------------------------- > > > > > : http://fer3.com/arc/m2.aspx?i=122449 > >
