202 Use of the Zenith Telescope in Determining Latitudes. 
tions on that pair. If the observations were numerous, of course 
the probable accidental error would be thus obtained with more 
re than in the actual case. 
he following table gives a convenient form for applying this 
method. The results were obtained by one of the sub-assistants 
in the U. S. Coast Survey, at Mount ln with the 
Zenith Telescope of the Coast Survey, No. 
For Probable Error of a Single Observation. 
No. of [Results for 
Pairs. | Latitude. 3 {a—z) | (a~ x)? SUMMARY. 
I {3792 
I, 11 nim Iv, sum of sqs. sd aie 
35:71 1'79 | 32041 | v, 1, 
33-01 “gl “8281 | vii1, = x, 
(4) 32°90 1:02 ¥-9400 | XI, XII, XIII, XIV, oan 
34-05 “33 016 ,XVI,xvi1, xvi, 6°7534 
33-92 Kid; &X, xX3, SETI, 78312 
36°15 t 05 0025 | Xx111, XXIV, xxv, XXxvI, __7°3678 
TH 27°84 164 | 2-6896 |xxvi, xxvit, xxVIII 55054 
(4) 34:59 161 | 25921 | xxix, xxx, XxxI, 242 
3G23 103 ‘0009 | XXXII, XXXIII, 23263 
36:20 Sauer z 
42°43 67 448 L(a—2z)? == 72°707 
IV 41-44 -36 0 : ade: 
41:50 24 0576 
(4) 1-60 “14 196 
41°74 
31° -28 0784 
32°80 Kay 3025 
(5) 32155 ‘2. 
31°44 “81 6561 
32-48 93 0529 
32°25 
29°81 1°39 | 1°9321 
28°22 20 
¥, 28°11 “31 
(©) 26-72 ro | 28 
29°24 “82 6204 
28-42 
34:3 19 
33-2 135°} 31-8225 
Vil 34:80 “20 
35:92 1:34 17956 
(4) | 3458 ~ 
21-5038 
Number of observations, <—=150 
‘ “ pairs, v= BP ays op 7673. —=0°6167 
r—v 
L— 
Then 0- ais te ayia on a single pair having but a single err 
tio 
The probable error of one observation —=A/-4549 X "4549 x 0° 0-6157= = "58 
* thé Tesult of a 5 pall having three ob- m7 
- servations upon abies Boe ee 
For eA mince upon a pal iy, ned ‘Gide a ee 
wa, ges? ais fete: » 
“teven. 
