12 
Mr Barlow On the Practical Construction 
Readings with the 
index turned to 
the right, when 
the colour dis- 
appeared. 
Observation for finding angle M. 
5° 10' 
5 16 
5 30 
5 SO 
5 16 
Readings with 
index turned 
to the left. 
117° 44' 
117 54 
117 30 
117 44 
117 40 
5)25 92 
Mean 5 18 
5)588 32 
Mean 117 42 
5 18 
2)112 24 
Angle M = 56 12 
Then, by the rule, 
Sin A = sin 24° 5T = 9-6235016 to tan B = 24° 49' = 9-6650346 
Add log 1.528 = 0.1841234 add cos M = 56° 12' = 9-7453056 
Sub. log 1*601 
9-8076250 tan 14° 25' 
0.2043913 
9-4103402 
Sin 23° 39' = a 9-6032337 
From angle a — 23° 39' 
Take angle b — 14 25 
angle c = 9 14 
From tan c = 9° 14' = 9-2110184 
Take tan a = 23 39 = 9-6414036 
Nat. n° 
From 
Take 
.37121 
1.00000 
.37121 
1.5696148 
Remainder, .62879 
Log of remainder 
.62879 = 1.7985056 
1.528 = 0.1841234 
Log of decimal of index B .601 = 1 .7788745 
Log; of index A 
o 
First sum, 
1.7615035 
