# 
yh 
a 
‘ 
j 
and parts of adjacent States. 371 
Table continued. 
Date. xX. pps Xi g4o-0 
am 
Utic 18436 | 3541 | +0005 | 3-546 
Schenectady 18436 | 3502 | +40°005 | 3:507 
1843-6 3-595 +0'005 3-580 
Wont Point, 1843-6 4:033 +0°005 4:038 
New York,” 1841-9 4014 0°00 4014 
Milford,* 1841 7 3-769 -O'00! 768 
Bushkill, 1841-7 3-866 -O'o0I 3°865 
Princeton, 18435 4222 +0°005 227 
Mean,| 3:81:18 
Recapitulation. 
Group. No. Latitude. Longitude. | Xj g40.9 
L 10 | 3957 | 76168 | 4158 
Ty. q 4o 15:4 79 54:9 4082 
Iii. 7 41 48:0 79 57°4 3853 
Lv, 10 4t 24-5 77 16°9 3-883 
ve 6 43 121 77 38-6 3-558 
Vs 8 41 416 4 24:8 3-818 
Mean,! 41 23-1 77 34-9 3-892 
Let X= Pye horizontal force. 
umed mean horizontal force for 1842 bf at the 
‘mean sn Jatitutle and mean lon jitude, z its correction 
= difference of latitude, dM= difference of longitude. 
X, ¥, 2, p,q and x to be determine ed from the observations. 
X=Xj+7+edL-+ydM cos L--zdLdM cos L+-pdL?+-gdM? cos? L. 
Forming the conditional and normal equations, we find the 
expression 
X=3'890 — 0: ai dL-+-0°0085 dM cos L+-0: ed dLdM cos L— 
0017 dL2-0-0027 dM? cos? 
Where 
dL=lat. —41°38 
dM=long.— —17 58. 
ip; the relative weights therefore become 754 for the former 
and 257 for the latter, or nearly as 
ae weights have been adop 
* At New York we have: te Locke, 4015; 1842-7, Dr. Locke, 4-008 ; 
reas Capt. Lefroy, 4-010; sia ets, be Tel. ; 
