244 REPORT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 
off arrangement^ Before the blast has reached the outlet just mentioned 
a part of it should be passed above the liquid and in the tight reservoir 
(by way of a tube, or by direct egress from the blast-tube when the 
latter is in or against the reservoir), to rise above the liquid (through it 
or through a tube), to give a pneumatic pressure upon the liquid, and so 
assist gravity in forcing a constant jet therefrom into the blast. 
When planning the construction of apparatus in which blast-pressure 
through one passage is to be used to eject the liquid through another 
into the blast the following principle should be observed : In order that 
the blast-pressure through the one passage shall be against the liquid 
more strongly than through the other passage, to squirt or help squirt 
the liquid from the latter, thus to feed the liquid to the blast, the blast- 
tube is constructed with greater capacity opposite and beyond the ejec- 
tion passage into itself, and this may also be accomplished by making 
any partial obstruction of the blast, by crook or otherwise, in that part 
of the main passage which is between the two reservoir communications, 
When it is desired the blast and liquid can be conducted together 
through very long^ubes, and, by the chambered forks or angles, may be 
equally divided, to supply one or more reverberatory jets at a distance. 
If the blast-pipe ends close to where the liquid feeds it, the latter 
will be blown in a fair spray $ but if the liquid must pass with it in the 
pipe for a considerable distance, and especially if there be any crook- 
edness in the course, the liquid becomes more or less condensed, and 
no satisfactory spray results without adding a special device for reat- 
omizing it, and this is best done by attaching the eddy-chamber nozzles, 
such as have been already recommended for squirting sprays, and others 
similar, but provided with different outlets. In any case, even if no 
conveyor-tubes are necessary, the best atomized spray is obtained by 
the employment of the reverberatory jets, which, like the feeding ar- 
rangement described, can be constructed with capacity for larger vol- 
umes of liquid and of spray than the old-fashioned atomizing principle 
will produce. The next best thing to the simplest reverberatory jets for 
this purpose is also new. It is the whistle jet, which differs from the 
eddy jet in having its outlets peripheral, and preferably close to the 
outside of the inlet, being the same plan of nozzle as that shown in plate 
XXXII, Fig. 6, and described above, but preferably with some mod- 
ifications. One distinctive characteristic of this is that it receives a 
blast across the inner face of the outlet hole. As will be seen, it makes 
one and the same stream return back to intercept and atomize itself. 
But while the foregoing styles seem preferable for agitation-chambers 
for these purposes, under certain limitations the number and location 
of the inlets may be altered, and the spray outlet or outlets may have 
any other position, such that the current must, in order to find exit, be 
given a suddenly tortuous or zigzag course by and in the chamber, 
while the form of the outlet may be cut in various shapes with good 
