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From: Roger Puttman (no email)
Date: Sun May 14 2006 - 06:41:02 EDT
Hi,
I'm brand new to this site so thanks for having me!
As a bit of an amateur I am keen to learn the more basic aspects of
astro navigation. I was lucky enough to serve as an assistant officer
of the watch on a Frigate and although I didn't get my ocean nav ticket
(a long story how I came to be there etc etc) I did get a good
grounding in astro. I recently bought a Hezzanith vernier sextant from
e bay and I have a couple of nav manuals, (1784 Mariners Compass
Rectified and 1842 Navigation by Raper and some modern ones too!) the
second is a complete course in the subject, starting at how to do the
maths and moving on to the instruments and tables for 1842 to 1845.
The first question I have is: I live on a hill overlooking the ocean
but dont know my elevation to set the dip. Given I know where I am and
can see some islands offshore is there a way I can determine my
altitude? I have a chart and can accurately place my house and the
islands so there must be a way....I just cant figure it out. I can get
off my bum and go down the beach and take sights but it is kind of fun
to be able to do it from the backyard...
Secondly, a number of you managed to extract Margetts tables from a
site but it seems to have been shut down. Is there anyway we can still
get access to that site? It sounds excellent for a whole pile of
stuff so it is a shame we get it now. As an aside, there was comment
on whether Margetts would have been used contemporaneously. I found
this from Mathew Flinders which given his abilty as a navigator might
be indicative:
I am not able to give you precise information of the books and
instruments you wish to purchase, but think they may come to near £80
sterling. I do not know much of Heather's charts: we reckon those of
Arrowsmith of Faden to be the best. Of the use of Margetts' tables I
have no great opinion, but Mendoza's are excellent. I would recommend
you to apply to Mottley, bookseller in High Street Portsmouth for both
books, charts, and instruments; believing that he will procure for you
what may not be kept in the shop; but I rather think you will not stay
long enough to receive what may be required from London.
Matthew Flinders - Private letter books, Nov. 1810 - May 1814 (Vol. 3)
To Mr Antony Roux, Sept. 26, 1811
cheers
Roger Puttman
32.46 S 115.75 E (decimal lat and long, my god what a dogs breakfast)
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