i8 
THE TELEGRAPH. 
the normal to the mirror passes through the meridian then 
occupied by the sun, the reflected beam will be projected 
towards the pole. 
A second mirror, the centre of which is on the prolongation 
Fig. 5. 
of the arbor of the first, and so inclined that the rays it receives 
from the first are reflected to the distant station, completes the 
apparatus. This second mirror, of course, remains in one fixed 
position. 
