180 C. K. Wead—Intensity of Sound. 
the pans were pulled down as far as they would remain, and 
when raised as high as they would remain. The value of the 
cere 2a’~ W’ is given in table I, col. 5; a’ is here in mm. 
‘in ke. The results under Mi, which are in { ] were 
Spiaieed by drawing the prongs together instead of separating 
them, as in all other cases; these are less reliable, because 
the friction of the strings which had to cross each other. A 
small correction must be made to these results in co]. 6; for the 
forces were not applied at the end, but usually eu m 
below it, and the measurement was made above the point of 
Spwplication of the force, usually 1 mm. Frc the end. It seems 
hardly roitengtuid to explain the details of the calculation, as it is 
easily made from the equations of the elastic curve, and of th 
angle ferent it sand its tangent at the point where the foree is 
applied. In only two cases does it amount to ‘010 mm.; on 
the Ut, the forces were applied 16 mm. below the ends of the 
prongs. 
TABLE I. 
1 2 ee ee ee 9 10 11 12 13 
2a’+W’, P : ae 
p’ P Dif. 
Fork! Length. |Method.|W’ 4 Energy 
- Obs. |Mean.| Cor. 2W?+-2a" on. From(?) +P (10) sn 
Sw Re ———r 
Mm. Kg.} Mm, Mm.| Kg. Mm. |107 107 x a? x 
Ut, | 203 |Blec. | 2 |-772 Pa 
3 | -772), -772]-125|-g97/ 2-22 | 228) 239} —10, 40 
Ut; | 141 |Mior. |.1 | 3265 
2 | 323 
3 | +327 
4 | +323 
4 | -324 
2 | +315 
4 | -316| -322 | 005 
Electr. | 2 | 320 Beals 
; 4 | -320| 320) -009| 328, 610 | 698] 677 | —13 | 1235 
Mi, {| 130 af $1317 age 
4 | -215| -216|-007| -223/ 9-97 | 8-80, 9-42 | —‘06| 1820 
[ “ 2 | +227 7 . 
rier € 4 | -235| 229 -011| 240) 8-33 oe 
Sol,| 116 “1 9 [174 othe | 
4 |*172] -173 | -007|-180' 12°11 | 109 | 12°46 | —‘14 | 2200 
Ut, | 104 “3 2 |°108 360 
} 4 | 098] -101 | “004|-105| 19:0 | 187 | 1916 | —-02|) 38) 
Sol,| 84 | 36-0 bse: 
Ut, 72 “ 2 | 026 0 : 
4 | -034! -080 | -002! 032] 625 | 613 | 642 | +712 1 1260 
All the oibee valida were _ - temperature of 16°--20° ©. 
Ig 
The other columns in table 
¢ P= 
‘+a’ =2+( 
EWP where the accents indicate Ky 
