308 
The following observations were taken Sept. 5th am. in 
Lat. 52° 12'10"N.; Long. 30s. (7° 30")E. The time given is 
local mean time. 
App. dist. of Sun from Moon. 
heen se Sun’s Alt. h, m. 5. 
42) 27 2 2) AOS 7 47 36 62° 54 40" 
7 53 44 Te BO Well 62° 53° 40° 
The observation of the Sun at 7h. 42m. 27s. giving the local 
time obtained from the Philosophical Society’s clock accurately 
within 7s., the levelling of the art. horizon, and so the altitude 
of the sun may be taken as nearly correct. 
The above observations reduced give 
At 7h. 48m. 19s. (L. M.T.) alt. of Sun’s centre 21° 59° 42", 
True app. dist. of centres of Sun and Moon 63° 25' 54", 
The Moon being in 28° N. Dec. and having just passed the 
meridian (at 7h. 44m. 11s.), the altitude was obtained by 
calculating the Reduction to the meridian, instead of by the 
more difficult method of observation, the change in alt. in 
4m. 8s. being only about 44". This gave the true altitude of 
the Moon’s centre 65° 47 50". Of course the altitude of the 
Moon could only have been approximately ascertained in this 
way, had not the longitude of the place of observation been 
accurately known. 
These data were worked out on four methods: Ist, on the 
plan given in Woodhouse’s Astronomy, which is believed to be 
based more or less nearly on the formula originally devised by 
the Chevalier Borda ; 2nd, on that given in the Introduction to 
Shortrede’s Lpaatatiiene Tables, mainly identical with the first 
method; 8rd and 4th, on the two methods given in Arts. 700, 
701 of Raper’s Navigation. 
_ No. 1 gives the longitude of the place of observation 1s. W. 
of Greenwich; error 31s. 
No. 2 gives it 3s. E. of Greenwich; error 27s. 
No. 3 makes it 12s. E. of Greenwich ; error 18s. 
