72 DONALD C. BARTON 
TABLE I 
ECN 
IL 
Error of Number Lengthof EC*N | Error of Number Lengthof EC*N 
Closure EC of Traverse ClosureEC _ of Traverse 

ORIGINAL DATA AND CALCULATED VALUES OF 




into ‘Cm. Stations L 1b in 10*Cm. Stations E 1G: 
Sec? N in Km. Sia N in Km. 
7-6 7 38.4 2.8 2.0 30 ame) 0.9 
3-8 72 45-1 0.5 2.9 go 32.0 0.7 
II.4 37 19.5 12.6 7-6 65 25-9 5-8 
7-6 44. 30.5 2.7 II.4 178 28.3 29.0 
Ir.4 45 36.0 5-2 2-4 201 105.2 1.0 
11.4 5 29.6 7.6 8.0 75 41.1 2.9 
7.6 56 28.7 4.0 3-0 102 2270 HBG] 
7-6 64 36.6 2.9 5-0 97 QT 5-4 
° 123 B72 ° 8.0 64 14.0 21.0 
3.8 65 19-5 0.2 6.0 80 19-5 On7 
7-6 82 22m 8.9 5-0 81 24.4 3.4 
7-6 73 22.6 8.3 7-6 61 35-6 2.8 
13.3 201 69.5 7-4 TS2 79 43.6 9-6 
36.1 164 65.5 50.5 II.4 56 28.0 9-3 
36.1 171 53-9 76.5 3-8 24 TL. 3 Dae 
Se 64 27-4 2.8 Seo) 36 17.0 4-1 
4-8 50 T:3)4| 6.4 E50) 39 ey 0.4 
8.0 79 58.5 1.5 5-7 32 15-5 4-4 
4.8 26 3-0 66.5 Tihs 130 7232 4-4 
1.6 35 4-9 3.8 7.6 113 51.8 2.4 
1.6 38 4.6 4-7 Typos 100 48.9 12.3 
4.8 71 9.4 18.5 ° 62 37-6 ° 
n=A45 PEges=0.6745V 418.7.45=2.2E ° 349 143-8 ° 
418.7 
TABLE II 
PROBABLE ERROR OF THE DETERMINATION OF THE GRADIENT IN SURVEYS WITH 
DIFFERENT STATION INTERVALS 
Station intervalin meters.... 150 300 400 500 600 700 800 
Number of traverses........ 5 12 8 12 6 2 I 
PerobaDI@errorr <). riee ieee. Seeey SESoeM GEG) GeroG) Smite) Sec Serle 
TABLE III 
PROBABLE ERROR OF DETERMINATION OF Ag BETWEEN PLACES BY GOOD TORSION 
BALANCE SURVEYS IN 10~4 Dynes (0.1 MILLEDYNE) 
Distance between placesin kilometers. 1 5 Io 20 40 80 00 
Probable error of: single direct trav- 
erse; or single traverse distance 
measured along traverse; or two 
more or less indirect traverses... .. tra +3 a? £6 8 eee 
DEVETAIELAVETSES, 6006 6 oi ei vec ose onesie +o.8 +2. +3 ta 26°) cee 
402 
