1874.] The Pole Star and the Pointers. 291 
under certain conditions, and ‘we will@first describe these 
when the pointers are east of the pole star. 
In the following diagram P represents the pole, s the pole 
star,a and @ the pointers, H N E the horizon, E the east, N 
FIG. 5. 
H N E 
the north, and H the west points. Under these conditions 
the pointers point with tolerable exactitude towards the pole 
star. When twelve hours have elapsed the pole star will be 
seen at S’ in its circle, the stars a and 6 will appear in the 
positions a’, 6’, and it is now evident that these two stars 
do not point at the pole star, although as before the angle 
Bera iS t45 43’. 
In six hours after the stars a’ and #' were in the position 
shown in the last diagram they would be on the meridian 
and below the pole, and as these two stars differ only two 
minutes in right ascension they would, when on the meridian 
and below the pole, point almost vertically upwards. The 
pole star, however, would now be go° in its circle from s' 
in the last diagram, consequently the pole star and the 
pointers would as regards each other then occupy the relative 
positions shown in the following diagram, where H 0 R 
Fic. 6. 
“A 
H co) R 
represents the horizon, 0 the north point of the horizon, 
P the pole of the heavens, s the pole star,a and P the 
pointers. The angle s Pa being as before 145° 43’. 
