1874.] The Pole Star and the Pointers. 293 
drawn on the sky commencing from the east part of the 
horizon, rising rapidly at first as an arch does rise, then as 
the equinoctial approached the south the arch would be 
traced nearly horizontally, then it would slowly descend, 
afterwards more rapidly, and finally cut the west point of 
the horizon. Therefore every portion of this equinoctial 
would appear a portion of a curve, and it could not be con- 
sidered a straight line any more than a rainbow appears a 
straight line. 
What shall we say, however, when we trace out the 
equinoctial on the sky as it would appear to a person at the 
North Pole ? 
To an observer at the North Pole the terms east and west 
do not exist. The south is beneath his feet, the north 
exactly over his head, and the east and west undefined. To 
him the equinoctial would not rise above his horizon as it 
would to an observer in middle latitudes, but the equino¢tial 
would coincide with his horizon in all directions. 
To every person who may be on the same level as the 
sea, and when a clear defined sea outline is visible, the 
horizon appears like a straight line, and all parts of the 
horizon appear like portions of a straight line: therefore to 
an observer at the Pole the equino¢tial will appear like a 
straight line, and will be coincident with the horizon, yet to 
an observer in middle latitudes the equinoctial will always 
appear as an arch in the heavens. 
' The same geometrical or optical laws which cause the 
equino¢ctial to appear a straight or a curved line, according 
as the observer is in one part or another part of the earth, 
also cause the pointers to appear under certain conditions 
to point exactly towards the pole star, whilst under other 
conditions they will not appear to point with equal accuracy 
to the same object. 
The same laws produce other effeéts in connection with 
certain celestial bodies, some of which effects are so palpable 
as to attract the attention of every observer, whilst other 
phenomena are noticed (spontaneously as we may term it) 
only by those who possess good observational powers. When, 
however, the peculiar facts are pointed out, and the celestial 
objects themselves illustrate the problem, few persons are 
incapable of perceiving the paradox, and the majority are 
anxious to learn the causes which produced it. 
In the present article we have confined our description to 
the pole star and the pointers, but on a future occasion we 
purpose treating two other phenomena even more easily 
observed than is the fact connected with the pointers; yet 
VOL. IV. (N.S.) 2P 
