570 
Mr. Airy on the 
Place. 
L 
L* 
Length in 
Fathoms. 
Peru . . 
India . . 
France . . 
England . 
Sweden . 
O t 11 
~0 2 31,22 
8 9 38,39 
38 39 56,11 
50 37 5,27 
65 31 30,27 
Oil/ 
3 4 31,9 
18 3 23,6 
51 2 9,2 
53 27 29,89 
67 8 49,55 
188510 
598630 
751567 
172751 
98870 
In the application of the method of least squares, it must be 
observed, that the accuracy of the terrestrial measures can 
scarcely be questioned, and that the chance of errors in the 
determination of the extreme latitudes, arising either from 
faults of observation or from local attractions, is principally 
to be considered. This however amounts to the same as 
supposing an error in the length of the meridian afc. Assum- 
ing the form, M x number of seconds in L' — L N (sin 2 U 
< — sin 2 L) + P ( sin 4 U— sin 4 L), the errors in the lengths 
are 
- I885IO -j- M X 11223,1 + N x ,1086 -fPx ,216 
— 598630 M x 35625,2 +Nx ,3084 + P x ,412 
■ — 751567 + M x 44533,1 + Nx ,0023 — P x ,837 
— 172751 + M x 10224,6 — N x ,0241 — P x ,175 
— 98870 + M x 5839,3 — N x ,0383 — P x ,009 
and the equations formed in the same manner as before are 
o=— 59255232 + M x 3516949,8 -|-Nx 1 1,8382— P x 22,016 
o=— -198869 |Mx 11838,2 -bNx>i° 9° + P x ,153 
0= 37285 — Mx 2201,6 + N x ,0153 + P x ,093 
from which M= 16,88164; N = — 9358; P --- 267 ; and 
the length of an arc of the meridian in fathoms = 
