1887. ] On some measurements of the notes of a whistle. 93 
WHISTLE A. 
Length of whistle 7-1 mm. 
Pressure of air blowing the whistle = 26-4 cm. of water. 
Dea : Observations of distance from the plate Mean Freres 
node. in mm. onstage, length. 
1 18-2 18-4 18-2 18:3 18°3 
2 33°] 34:0 32°77 = 33.48 30°6 16°8 
3 48-0 50:0 51:7 49-0 49:7 16-6 
4 68°5 66-0 68:0 64:5 65:1 66°4 16°6 
5 83-2 81:0 82-2 83:8 82°5 16°5 
6 101-0 99-3 100:2 Low 
7 WAGES Pye eS ey) 117°9 16°6 
In this and some other cases the length calculated from the 
first node is far greater than that from any of the others. This 
may be due to the heating effect of the flame which cannot well 
be allowed for. We thought better therefore to leave out the first 
position in all cases. The mean result of this series then will be 
Half wave-length = 16°63 mm. 
TABLE OF RESULTS. 
Whistle | Pressure of air in | Length of whistle | Quarter wave-length 
used. em. of water. in mm. in free air in mm. 
A 16-7 30 3°96 
i 16°9 3°3 4-15 
is 27D 5:0 6-65 
4 26-0 6-53 
i 19°3 " 7-40 
32-8 rd 6:30 
fi 21-4 Ps 7-05 
29-1 4! 6°32 
55 22°8 55 6:50 
A 26°4 ek 8°32 
B 24-5 2 8-22 
" 15:9 . 8-77 
A 27°0 76 8°55 
