THE HON. J. W. STRUTT ON THE THEORY OF RESONANCE. 
117 
Thus 
1033 x 12 
6-26 
1133x 12 
6-28 
a/ 
v/ 
16-39 X U008 
3200 
16-39 X 2-438 
3200 
= 155-6, 
= 241-9. 
The agreement is now very good. 
One of the outer holes was stopped with a plate of glass. The resonance of the high 
note was feeble though well defined ; that of the low was rather loud but badly defined. 
The high note was put at 225] 
,, low ,, ,, 90 j 
S=3150, S'=3250, 
c 2 =‘7152, Cj = T008, +^=1-7232. 
Calculating from these data, we get 
=225-2,1 
n 2 = 90-5.J 
The agreement is here much better than was expected, and must be in part fortuitous. 
I will now detail two experiments made to verify the formula marked (20a). A mode- 
rator chimney was plugged at the lower end with gutta percha, through which passed a 
small tube for application to the ear. The bulb was here represented by the enlarge- 
ment where the chimney fits on to the lamp. On measurement, 
—=4-16 inches, L= 5- 36 7 inches, a=^R=-471. 
Thus 
ta D kx 9-611 =nTl6i ; 
from this the value of k was calculated by the trigonometrical tables. Finally, 
w=251-4. 
As the result of observation n had been estimated at 252. 
In another case, 
L=5-767, a=-537, 3*737, n by observation =351. 
The result of calculation is n— 350-3. These are the only two instances in which I 
have tried the formula (20a). It is somewhat troublesome in use, but appears to repre- 
sent the facts very closely ; though I do not pretend that the above would be average 
samples of a large series. There is no necessity for the irregularity at the lower end 
taking the form of an enlargement. For example, the formula might be applied to a 
truly cylindrical pipe with a ball of solid material resting at the bottom.] 
I had intended to have made these experiments more complete, particularly on mul- 
tiple resonance, but have not hitherto had time. However, the results obtained seem 
MDCCCLXXI. g 
