Transit Observation without personal error. 49 
nothing to do, except possibly to note 
_ Nite, for each records itself on the chronograph without ae 
intervention of his. But if the star be, for instance, two-thirds 
- the way from the first to the second wire at the first flash, 
m will draw one of the cords, accelerating the flash and thus 
Causing the star to appear nearly coincident with the second 
vite when the next spark comes, and repeat the adjustment by 
the light of subsequent flashes, till the bisection 1s perfect. 
ree or four trials are in practice found to yield a bisection 
Which will satisfy a fastidious eye, and when a satisfactory one 
