
Mechanically Reinforcing Sounds. 285 
In this case, however, it is closed with a pierced cork, into 
which fits a ‘ Y” connector, one branch of which, y, is con- 
nected by tubing to the jet ‘a,’ whilst the other branch, y’, 
is Jomed to a second Y-fork, called in the diagram Z; of the 
two remaining branches of this one leads to an ordinary 
gas-supply nozzle, whilst the other is jomed to a third 
Fig, 1. 
70 GAS 
TO GAS 

TO AIP BAG = TO GAS 
Y-piece, the stem of which is connected with a large gas- 
bag, containing air under very considerable pressure 
(generally a cwt. and a half being placed on the pressure- 
boards). The third arm of this Y-piece, namely K, leads to 
a fourth Y-piece “ L,” the stem of which is joined to the jet 
“6,” whilst its other arm is connected to a second gas-supply 
nozzle. A small third jet ¢ rises vertically beneath the 
other two, and almost touches them ; thisis joined by tubing 
to a third gas-supply nozzle. P, P, P, are screw pinch- 
cocks. The jets I have used have hitherto been made of 
glass, and in fig. 2 they are drawn life-size—in (a) a vertical 
section, in (b) as seen when viewed from a point immediately 
above them. In both these figures the relative positions and 
dimensions of the jets have been carefully depicted. The 
third jet c¢, fig. 1, is an ordinary glass jet, and, so far as I 
have seen, need not be of any special dimensions or shape, 
but } and a should be made as nearly as possible as drawn. 
Ordinary black indiarubber-tubing serves well for the con- 
nexions, and for the three-way pieces, those sold by the 
Edison-Bell Phonograph Co., 39 Charing Cross-road, serve 
very well. In using the apparatus the gas should be turned on 
Phil. Mag. 8. 6. Vol. 7. No. 39. March 1904. Xx 
