The Hillsdale standard. [volume] (Hillsdale, Mich.) 1851-1909, 1860-04-10
The Way TO Tell the time OF Night by the
Stars.


With suitable instruments the time can
be ascortained more accurately by the stars
than in any other way; and il is easy to
tell 1t appr Ximatoly--say within half an
hour--withoat any instruments whatever.
Let us describe a simple, rough device for
this purpose, rs the easiest mode OF ox.
planning how ii may be done by the un-
aided action OF the eye and judgement.
Take a keg or barrel hoop, or n hoop Of
wire, and divide it into "a equal spaces,
marking the dividing points for four points.
Connect the opposite hour points by lines
of iine twine drawn accross the diameter Of
the hoop, Hang the apparatus against
a north window, and place the eye in n
line with the middle of the hoop (wAero
the wires cross each other) aud tho moth
star. Now any Of the fixed stma, in lis
daily revolution about the pole, will form
ono wire to the next in an hour. Let US
select the nearest pointer in the "dipper'
(Alpha Ursa Major) for thv hour hand on
our great clock of the heavens. Place the
eye at such distances from the apparatus
as TO bring the star just within the hoop,
keeping tho center of the hoop III Il line
with the North Pole. On The 9th OF
March, the star Alpha Ursa Major will be
on the meridian, directly over the north
star, and consequently in line with the up
per vertical wro Of our apparatus, at -
o'clock, midnght and rs it passes from
one wire to the next in On hour, if it is seen
in line with the first wire at tho right of
the vertical orc, the time will he IL o.
clock; if in line with the second wire Mt
tho right, 10 o'clock, and SO on. While if
it has passed the middle, and reached the
first wire at the left the time indicated is
l o'clock; the second wire > o'clock, and
50 on.
This star, in common with all the olhor
fixed stars, comes to the meridian about
four minutes earlier each night or day than
it did on the preceding night OF day
Consequently, on the 9Th of April it will
reach the vertical wires at 10 O'Clock at
night, and tie other wires at corresponding
times; and this variation continues at the
rate Of two hours each month throughout
the year.
From this description tho mode will be
readily understood Of telling the time Of
night By tho stars without the aid o! in
srument5. We require to learn two stars
the pole star, and that ono Of tho poin.
tcrs which is the nearer ono to ito re-.
men Der that this lttter star is directly
over the north star at midnight on the 9TH
of March, and comes to the meridian two
hours earlier on tie 9TH Of each month
than i, Ill On the 9th or the preceding
month. As the star reyolyes around the
circle in > hours, it will of course, reyolyc
one fourth the distance in hours, being
at right angles 70 the meridian C houIs
from the time it is on the meridian, anl at
an angle If ~ dec, hours from that
time.
Tho apparatus which We have described
will be more accurate if the top j, inclined
towards the perpendicular a, an angle car
responding vi'h The latitude Of thc place
in which the observer is located, bringing
it perpendicular to tho aAle Of the earth,
aud in u plano paaI!e. with tho plano OF
tic equator.