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Re: SNO-T Manual, Heath Brochure CLEANING SEXTANTS
From: Joel Jacobs
Date: 2004 Aug 6, 08:15 -0400
From: Joel Jacobs
Date: 2004 Aug 6, 08:15 -0400
Lee,
Thanks much for pointing me
at the other site.
I am sorry to be a
bother again, but I still have a problem. The SNO-T link results in a 404
Error. Since I was able to read the Heath manual, I doubt my pdf system's at
fault.
IMO, the Heath manual
is full of worthwhile material, including mounting a stop watch on a
sextant. It does a very good job in discussing scopes. The manual
states the clear portion of the horizon glass is an advantage since it reflects
back the other half of the image which is lost if the horizon mirror only has a
silvered side. Remember the lengthy exchange of this topic started by Jim
Thompson. I couldn't find a date on the manual, can you confirm where you
obtained the 1936 date you mentioned?
However, the
manual is light on the topic of taking care of a sextant. This is
surprising since they talk about a very special mirror, "Sea Safe" with a
laminated cover glass and notched sealed and glued edges to make it water proof,
and then only superficially discuss the care and feeding of standard mirrors. So
lets get back to sextant cleaning and the use of water to rid the instrument of
salt for a movement. Surprisingly, this went unmentioned in the Heath manual.
For those interested, I suggest reading Article 1610 of Bowditch, and
also the extensive discussion by Bruce Bauer in the "Sextant Handbook".
Bauer goes so far
as suggesting placing the sextant in a bucket of fresh water if it
was splashed with seawater. That's a measure that sounds pretty
extreme.
Thanks
Lee,
Joel
Jacobs
----- Original Message -----From: Lee MartinSent: Thursday, August 05, 2004 10:46 PMSubject: SNO-T Manual, Heath BrochureJoel apparently had trouble with downloading the SNO-T manual from Gerard's site, others found it worked fine. There is an alternative site for download at www.pcug.org.au/~martin/Sextants/ . Also on that page is a 1936 Heath and Co brochure on the care and maintenance of sextants, with particular reference to Heath sextants.Lee Martin
