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