278 ON THE COMBINATIONS OF 
6.125 x. 1.8422 
1125 x 1.0000 
11.2834750 
1.125 
II 
7-250 12.4084750 
12.4084750+7.25=1.7115 mean specific gra- 
vity as given in the table. 
In the same case, the example according to 
the correct rule is thus, 
6.125 + 1.8422 = 3.3248 
1.125. + 1.0000 = | 1.125 
7.250 4.4498 
7.25+4.4498=1.6292 the true mean specific 
gravity. 
By the calculation column being corrected, 
the table would stand thus, 
Sp. Gravity by|Specitic Gravity 
Dr.Thomson’s} by correct Difference. 
Experiment. | Calculation. 
1.8422 
1.7837 1.6292 + 0.1545 
1.6588 1.5022 + 0.1566 
1.5593 1.4179 + 0.1414 
1.4737 1.3578 + 0.1159 
1.4170 1.3128 + 0.1042 
1.3730 1.2779 +0.0951 
1.3417 1.2500 +0.0917 
1.3105 1.2272 + 0.0833 
1.2845 1.2082 + 0.0763 
