Erect fore-and-aft hair
RESTRICTED
(b) The discussion is limited to
series later than M-3.
these series cannot move inthe fore and aft plane.
They can be moved laterally and therefore all that
has been
said in the preceding paragraphs applies
to the erection of the fore and aft hair of these
later series.
And what has been said in the pre-
ceding paragraph also applies to the erection of
the transverse
hair of these
later series pro-
vided that it be understood it is the line of
sight along the transverse hair as reflected
it is being sought to erect to the vertical.
The
telescope
tube
that
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