286 The Pole Star and the Pointers. (July, 
the changes in various celestial bodies, due to the half rota- 
tion of the earth, which had occurred from 8 P.M. to 8 A.M. 
The pole star and the pointers particularly attracted our 
attention, for we could easily perceive how the pole star 
appeared to sink nearer and nearer to the horizon as we 
passed each day two or three degrees nearer the equator, 
and we realised one of the first elementary laws of Astro- 
nomy, viz., that the altitude of the pole above the northern 
horizon was always equal to the latitude of the place from 
which the pole was seen. In 52° N. latitude the altitude of 
the pole was therefore 52°, whilst in N. latitude 40° the alti- 
tude of the pole is only 40’, and so on. 
Whilst observing the pole star and the pointers, at inter- 
vals of about twelve hours, and when consequently the 
pointers were at one time east of the pole star and at other — 
times west of it, we noticed that at one time, and under one 
condition, the pointers appeared to point more dire¢tly to- 
wards the pole star than they did at other times. When 
this peculiarity was at first noticed we believed it was in 
consequence of our want of observation; for we naturally 
argued that, as the fixed stars did not alter their relative 
position as regards each other, it must follow that if the 
pointers pointed towards the pole star at one time, they 
must do so with equal exactitude at another time. To 
imagine that the mere rotation of the earth on its axis 
could cause any alteration in the relative position of three 
stars in the heavens seemed almost an absurdity, and al- 
though night after night, and morning after morning, we 
observed that it really appeared as if the pointers did point 
in a variable manner as regards the pole star, yet the fact 
was passed over—as facts too often are—by those who 
cannot account for them. 
It was several years after our first notice of the pole star 
and the pointers that our attention was again directed to 
these celestial bodies, and we once more noticed the same 
facts as those already referred to, and very shortly recog- 
nised the law or cause which produced the appearance, and 
found how more than one interesting problem depended 
thereon. 
In order that the whole of the problems resulting from 
the above law should be thoroughly understood, the reader 
ought to be acquainted with what we may term the geometry 
of the sphere, and also the various terms used in Astronomy, 
but to comprehend these problems will require but average 
intelligence, a careful perusal of the following pages, and a 
sufficient amount of imagination to picture, as it were, on — 
