332 Observations on the present Siale 
It will be observed, that out of the above fifty independent sets 
of observations, taken at different times during nearly six weeks, 
the deviation of any one from the mean of the whole, iz one in- 
stance only, amounts to twelve miles ; and that the average de- 
viation, either in excess or defect, is less than five miles. It will 
be observed also, that the longitudes obtained by distances from 
stars are quite as uniform as those deduced from distances of the 
sun. The observations comprise the whole that were taken in 
the interval between the first and the last of the days of obser- 
vation; not one has been omitted. Their results may there- 
fore be considered as a fair specimen of what, under ordinary 
circumstances, the method is capable of effecting; and making 
every reasonable allowance, we may infer from them with consi- 
derable confidence, that a practised observer will generally de- 
termine his longitude by one set of Junar distances to within less © 
than ten miles; and that it is quite improbable that the error of 
any one set will ever considerably exceed a quarter of a degree. 
The mean result of a number of independent sets, will of course 
reduce the probable error within still narrower limits. 
The following distances, measured on the Sth and 9th of May, 
were taken under extremely favourable circumstances ; and the 
two observations made on June 26th were made, when, from the 
situation of the School with respect to the smoke of the town, 
and the smallness of the moon’s illumined disk, she could not 
be seen with the naked eye. It will be observed that the devia- 
tions from the mean are here very considerably smaller than 
those in the former series. 
a App. Time 
s ‘ 
Paenuiihey Day. at App. Dist. 
Newcastle. 
He M. S: Sree iy 
© and )p May 8 26 21 | 86 4 13 
eee one AaB ove 210 91] 8 5 42 
* 7 ene 243 24) 86 18 46 
ee eps a 419 5 | 86 54 43 
se wee se , 4 26 34] 86 57 @2 
ee ave r 4 5S 48 we So elias 
ats be 455 56| 87 7 2 
>) Spica “ 844 8/65 1 28 
a nial 8 59 17 | 64 55 O 
ese ° 9 41 16 | 64 36 39 
ece . - 9 47 56 | 64 35 51 
me on , re 9 54 2) 6431 0 
eas. . > 9 59 39 | 64 28 20 
oy 9 | 2 27 47| 97 37 49 
ae 2 . e 237 41] 97 41 36 
nes ad 2 49 34 | 97 46 38 
& ats a 8 0387) 97 51 5 
° ee 3143 97 56 38 
ate June 26 211 25 | 41 29 20 
axe F 2 34 28 | 41 17.18 
