NavList:

   

Reply

Thanks to Alex Eremenko for digging out the following gem frem Norie's.

>the following method by which one person can take a set of
>observations without assistants: HAVING A GOOD QUADRANT TO TAKE
>THE ALTITUDES AND A SEXTANT TO OBSERVE THE DISTANCES..."

What edition of Norie was that in? In my 1900 edition, presumably much
later than the one Alex was reading, the reference is only to a team of 3
or 4 observers.

To me, the suggestion that the single observer should pick up a quadrant
for his altitudes, when he already has a perfectly good sextant to hand for
the lunar distance, appears to be utter nonsense. I can think of no reason
at all for such a procedure.

It's perfectly true, however, that navigators would keep their best sextant
(or even quintant) for their lunars, and an inferior instrument on
occasions when only altitudes were being measured, and even a wooden
quadrant was good enough. The measurements of altitude that were needed for
correcting a lunar were particularly undemanding.

However, for a one-man observation, once the sextant had been taken out of
its box for the lunar distance, I can see no reason why a different
instrument should be used for the altitudes. I agree with Alex. that it's a
strange comment. Perhaps it's been cobbled together from earlier texts by
someone (later than Norie himself) who didn't know what he was talking
about. These things happen, all too often.

George.





================================================================
contact George Huxtable by email at george@huxtable.u-net.com, by phone at
01865 820222 (from outside UK, +44 1865 820222), or by mail at 1 Sandy
Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.
================================================================

   

Reply