NEWTONIAN CONSTANT OF GRAVITATION. 51 
Part III. 
The calculation of the results from the figures obtained by observation is divided 
into four sections:—(1.) The deflections and periods; (2.) The geometry of the 
apparatus; (3.) The dynamics of the moving system; and (4.) The combination of 
these resulting in the determination of G, the Newtonian constant of gravitation, 
and indirectly of A, the mean density of the earth. In the preparation of this part 
I have been greatly helped by Mr. 8. G. Srartte, of the Royal College of Science, 
who has carried out the laborious numerical calculations. 
_ 1. The Deflections and Periods. 
The treatment of the figures obtained during the observations of deflection will be 
best explained by an example. I give two consecutive sets, one the worst obtained 
the whole night, and the other a particularly good one, but others obtained that 
night were practically as good. 
Sept. 17, 1893. 











| | 
A = 150°-9. 13h. Om. | 15°15 C. 
{ 
| 24907 —94 | 24893 
le ANG 390 24493 
| 24193 —26 | 24167 | 835 
| | 598 | 396 24.493 
94789 | —24 24.765 e394 | 
| | 499 271°5 244935 
| 24202 | -26 | 24066 | ‘838 
* | | 418 | 226 24.492 
24709*+ —25 24684 | | 848 | 
| oro aa senae| 192°3 (24491-7) 
| 243554 | 255 | 949095 | | ‘842 
298-5 | ————e 
24.6544 —26 2.1628 | 24.492-9 | 
A =20°9, | 13h. 15m. 15°15 C. . | 
| | 
19888 76) = | Tess | 
| 1702 926-4 20795°4 
21591 20 21571 | 8873 | 
1425 | 7753 20795-7 
20165 ~19 | 20146 | 9379 | 
194 |  649:5 20795:5 
21359 —19 21340 2384 | | 
1001 | 5445 | 207955 
20358 = 20339 8382 | | | 
839 |__| 
21197 —19 21178 20795°5 


* A short period oscillation or tremor, set up probably by a passing train, 
+ A pendular oscillation, set up probably by a passing train, 
BH 2 
