108     ON THE  EFFECT  OF  THE  INTERNAL  FRICTION  OF FLUIDS
Dubuat's experiments on this subject consist of 44 experiments on spheres oscillating in water (Tom. II. p. 236) ; 31 experiments on other solids oscillating in water (p. 246); and 3 experiments on spheres oscillating in air (p. 283). The following table contains a comparison of the formula (148) with Dubuat's results for spheres oscillating in water. The value of v ' yt employed in the calculation is 0*0564 inch English, or 0*05291 inch French.
Dubuat's experiments on spheres oscillating in water.
| IX
T | ^                                       ->, calc.             obs.             diff.

Sphere of lead                               f t Diameter 1-0113 inches                 j « Weight in water 2102 grains       ( ^

1-633
1*687 1-766 1-825

1-502 1-502 1-522 1-620

- 131 ~*185 -•244 -•205

Sphere of glass                               ( 2 | 1-602 | 1-518 | -•084
Diameter 2*645 inches                   < 4 | 1-644 | 1-569 | -•075
Weight in water 574 grains          ( 6 | 1-676 | 1-598 | -•078
f 1 | 1-572 | 1-515 | -•057
Same sphere weighing in water   J 2 | 1-602 | 1-516 | -•086
2102 grains                                   ] 3 | 1-624 | 1-523 | -•101
U | 1-644 | 1-546 | -•098
(1 | 1-572 | 1-537 | - *035
Same sphere weighing in water   ] 2 | 1-602 | 1-523 | -•079
4204 grains                                  1 3 | 1-624 | 1-524 | -•100
U | 1-644 | 1-538 | -•106
ft | 1-551 | 1-449 | -•102
Same sphere weighing in water   I 1 | 1-572 | 1-372 | -•200
9216 grains                                    ] 2 | 1-602 | 1-494 | -•108
(3 | 1-624 | 1-494 | -•130
12 « 4 Q | 1-566 1-581 1-593 1-614 | 1-507 1-547 1-547 1-567 | - -059 -•034 -•046 -•057
I      \ | 1-547 | 1-375 | -•172

2 Same sphere weighing in water    I ~
4204 grains                                   ]   .

1-566 1-581 1-593

1-456 1-525 1557

-•no
-•056 - -036

-6 | 1-614 | 1-549 | - '065
(1 | 1-547 | 1-57 | -f'023
Same sphere weighing in water   J 2 | 1-566 | 1-553 | -•013
9216 grains                                  1 3 | 1-581 | 1-59 | + •009
U | 1-593 | 1-583 | -•010