i iS Sir George Shuckburgh's Account 
Also the second reading off of the microscope - == 0,5 
And the total error of an observation of a transit out 
of the meridian, will be - - ■ - = 5,0 
The same, from actual experiment, in 13 trials, 
within 15 0 , on each side of the meridian (in Feb- 
ruary, 1792) - - - - - =7’5 
That is, that an observation made out of the meridian, will 
give the transit over the meridian true to { a second of 
time. 
The error in the observation of a polar distance may be put 
as follows. 
Error of the eye, in estimating the coincidence of 
the wire in the telescope with the object, the power ,, 
being 60 times - - - - = 1, 
Error of the divisions, and of the centre, in taking 
the horizontal point in the circle - - - = 1,- 
Error in reading this division off by the micro- 
scope - - - - = 0,5 
Error of the level, in ordinary observations - =2, 
Error of the divisions, and centre, a second time, 
viz. in taking the angle of the polar distance - =1, 
Error in reading off this division by the microscope = 0,5 
Sum of all these errors - - — 6,0 
Ditto, by actual observation of the line of collima- 
tion, the circle being turned east and west, from va- „ 
rious experiments, appears to be - - 7,5 
Lastly, if care be taken in the observation, and the 
