226 HINTS TO TRAVELLERS. 
Example 3.—The log. cosec. of 97° 4' is the log. cosec. of 82° 56', or the 
log. sec. of 7° 4', which is 0*003312. 
In like manner to find the log. co-sine, co-tangent, or co-secant, of an 
arc above 90°, take out the log. sine, tangent, or secant, of the excess 
above 90°. 
To find the log. sine, &c. of an arc given to seconds. Find the log. sine 
(or cosine, &c.) for the next less minute or half-minute; take out the 
parts for the seconds, or for the excess above 30". 
For the sine, tangent, and secant, add the parts. 
For the co-sine, co-tangent, and co-secant, subtract them. 
Example 1.—Find the log. sine of 53° 25' 13". 
o t it 
53 25 o sine .. 9*904711 
13 parts . +20 
Log. sine req.9*904731 
Example 2.—Find the log. tan. of 11° 19' 54". 
O / It 
11 19 30 tan.9*301624 
24 parts . +262 
Log. tan. req.9*301886 
Example 3. —Find the log. sec. of 38° 42' 46". 
O t II 
38 42 30 . 
3 6 parts. 
Log. sec. req. 
Example 4.—Find the log. cosine of 72° 10' 45". 
O I ft 
72 IO 30 .. .. . 
15 parts. 
Log. cos. req.. . 
Example 5.—Find the log. cotang, of 84° 3' 22". 
O il ! 
84 3 ocot... .. 
20 parts 408 \ 
2 41/. 
0*107716 
+J7 
0*107743- 
9*485879 
-98 
9*48578$ 
9’ 01 7959 
-449 
Log. cotang. req. 
9*017510 
