Next message: Richard Langley: "Re: GPS shortcomings."
Metal vs. Plastic is addressed in Joel Jacob's book, "The Myths and The
Truth about Selecting a Marine Sextant". My copy is dated 1975, so perhaps
a lot of advances have been made in the plastics industry since then. As
Mr. Jacobs is an active list member, perhaps he will wade into this
discussion.
Robert
----- Original Message -----
From: "Peter Fogg" <>
To: <>
Sent: Thursday, June 09, 2005 3:00 AM
Subject: Re: GPS shortcomings.
>> >>On Behalf Of Lu Abel
>>
>> Do you speak from experience or just theory about "plastic?"
>>
> When I've had the chance to examine them I've found them disconcerting to
> use - for example, the index error was different each time I checked on
> one
> instrument, before and after taking a sight. It didn't inspire confidance.
> I
> know and accept that they have been used to cross oceans with, and
> possibly
> they are ideal for the task of teaching students.
