M. C. Ihlseng— Velocity of Sound in Wood. 
127 
communicates it to the air in the glass tube, I, the dust figures 
then are formed at the nodes A, B, B’, B”, ete. 
The distances 
AB and B’ B” are the semi-wave lengths of air corresponding 
to the note given by the rod. Although the length AB” does 
not materially affect the length of the waves, it has been found 
best to make it equal to a multiple of the semi-wave lengths as 
then the figures are most definite. The glass tube was 1™ 
TABLE I. 
Name of wood. No. rod. Length. Section. Sp. Gr. 
OMay. ous ce 1 1836-0mm 14°25x21-45mm | -432 
Be ane eg 2 38°4 14°15 x 21°45 “482 
agenrt ence ne ge 2t- 3 1838°75 5°6 x 20°45 “465 
gies re ee 4 1836°72 143 x 21°6 “ANT 
ee te eee 24 1650°0 14-3 x 211 ‘478 
White wood, _._. 5 1876-92 2-4 x 26°35 
4 Roge 6 1838°5 1°77 x 26°42 “476 
a sts. 7 1834-0 2°35 x 26°85 “443 
“ oe 8 1162°25 12°38 x 13°17 
“ ps 9 1162°55 13°0 x 13°14 
a Sy 8 1142°37 12°28 x 13-00 -478 
4 ert 11 1164-94 12°79 x 13-23 
ad cree 12 1184°73 12°94 x 13 
White pine, ....| 13 1842-6 17°86 x 21°27 “491 
Meee WEG sy EG 1841°9 17°45 x 23 432 
Yellow « 23 1052°45 }2°17 x 24°11 664, 
Stkorysp3ii 5 it 38 1550°5 24°27 x 12°95 922 
White ash,__.___ 16 1836°5 9°55 x 19°65 “544 
C 17 1838-26 9°55 x 19°70 “541 
wets Bee caw 2 18 1809°7 14°98 x 17°6 “593 
te holly,.....; 19 1378°5 10°30 x 10°91 “562 
Mahogany, .____- 20 1349°1 11°54 x 11°52 540 
Black Walnut, ___ 21 1378°63 10°82 x 9 518 
Cherry; £20976 22 1560°1 10°92 x 11°49 “693 
Bad Olle 4. 25 14947 1 x 18°28 “650 
White oak, __.___ 26 1494°5 12°68 x 17°98 “115 
Velocities obtained by Kundt’s method. 
TasreE IL. 
Rods onumber of | ‘Temperature. Velocity. Probable error. 
No. 1 25 15°°5 C. 39063 M. 24 M. 
es 40 20°7 27°6 8-08 
i 23 25 16-1 3966-4 4°62 
“4 25 58 4071° 9°90 
~ 2 25 3°5 5164°6 2°58 
oe 30 56 5129-9 12°29 
“4 35 63 249-3 2°6 
oe 30 4:0 4912-31 4°3 
ee 35 4-4 4739-63 43 
7 20 30 46 4712°53 24 
eae 25 14°5 5309-4 9 
7 25 [4°3 484571 3-4 
mee 35 15°4 4783°15 25 
eae 25 16-4 4110-07 2:1 
