E. S. Snell on the pri at Holyoke. - 229 
Time of ob- Temperature Depth on Observ’d No, vi-,; Cuiculated wo, 
| servation. of ae: : Dam. brations per _min.| vibr. per. min. 
1 July 25, 1857, 80°: 2 feet 137 136 
2 ‘July 29, « 15 RP 136 136 
5. (Any. 6. ¢ 16 Tose 257 271 
4°1Oct. 7, ‘= 65 1‘ 258 268 
5 {Nov-24, * 30 z-* 140 129 
6 Apr. 16, 1859, 45 bod 82 6 
| 7 \July 25, 1859, 40 3 inches none none 
v 
I used the formula in Peirce’s Treatise on Sound, N=n aE 
where N is the number of vibrations, n the number of nodes, V 
the velocity of sound, and L the length of the tube. It is observ- 
able, that the calculated rates are higher than the observed, in 
the cases of most rapid vibration, and lower, in those of least 
Tapidity, while in the medium rates, they very closely agree. 
As to the eres case, the sheet was so thin, that it was divi- 
ine thus destroyed, no vibrations could p 
Notwithstanding the discrepancies between the sastibait in 
oe and the mode of exciting vibrations 
ms to be one of the numerous cases, in which the body 
which | excites vibrations in aerate is itself thrown into syn- 
chronous vibration by reaction, and then, by its own inertia ¢ 
icity, controls the common rate of both. — ee 
in its descent first produces rarefaction of the e by re- 
i i a collapse 0 f the 
it. The immediate effect is 
‘Sheet of water, as well as a rash of air in at the ends. ‘But the 
inertia of a thick mass of water W vent its recovering its 
tural position so soon as if it ur stot eet hence, the air- 
column di vides _— into such a number of segments, that the 
Water an can adjust their movements to each other, 
