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I am reading Norie (and enjoy it very much,
especially the math pages:-)

One strange passage attracted my attention:

"In taking lunar observations, two assistants should employed
to observe the altitudes...also one with a watch...
...
The Quadrants and Sextant being properly adjusted...
...
It may sometimes happen, that for want of proper assistants
the altitudes of the two objects cannot be taken at the same time
as their distance...
...
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..."

(End of cite).
In general, the book makes an impression that altitudes
are taken with a "good Quadrant", while a sextant is only
for the lunar distances.

I understand that a wooden quadrant was much cheaper than
a brass sextant with a platinum or palladium arc, with
a nonius reading to 10",
but why ONE observer should use two different instruments
for altitudes and distances??

Any comments by the lunars/history experts?

This reminds me a joke about Newton who had a cat.
To avoid to be distracted from his meditations by the cat,
he made a hole in his door, so that the cat could walk out
when she needed. Then the cat bore a kitten...
and Newton made a second, smaller hole for the kitten.

Alex.

P.S. Averaging observations should be ALWAYS profitable for the
lunars and Norie recommends taking 4-5 distances in row.

P.P.S. I remember a question about pencils on this list.
Norie mentions pencils several times.

   

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