n8o 
Journal of Agricultural Research 
Vol. V, No. 25 
nozzle comes through decreasing the size of all but the smallest particles 
and thus increasing the proportion of minute particles until, as in the 
cyclone nozzle, practically all of the material is in the most finely divided 
state and is therefore also uniform. This improvement can be produced 
by increasing the pressure or decreasing the size of the stream. Under 
the same pressure a nozzle with a large orifice gives coarser drops than 
a similar nozzle with a small orifice. Therefore, where a larger volume 
of spray is desired, it has been the practice to duplicate the nozzles 
rather than enlarge them, giving clusters of nozzles; but where high 
pressure is available, large nozzles, particularly those of the better type, 
may be used. With extreme pressures, such as were employed in the 
gipsy-moth work and in the walnut spraying in California, a nozzle of 
the poorest quality and rather large size has proved to be practical. 
In nearly all cases the desirability of fine and uniform sprays, in order to 
secure evenness of distribution, has been recognized. It is possible, 
however, that under some circumstances a driving spray may be de¬ 
sirable, and this can be secured only by the use of less efficient nozzles. 
VARIATION IN FINENESS 
The sizes of the smallest drops in a spray are not necessarily the same, 
particularly when made by the breaking up of a sheet of water. By a 
change in the proportions of the eddy chamber in a cyclone nozzle or 
by a change in spraying pressure the diameter of the cone at the point 
of breaking can be changed, and the drops will remain uniform, but will 
be of a different size than before. In the new type of nozzle here 
described the angle of impact and the spraying pressure exert similar 
effects, and a series of nozzles can be produced covering much the same 
range obtainable in a cyclone nozzle and distinguishable by the width 
and length of the fan. 
Only relatively small drops in the spray in either case are obtained, 
and these show great uniformity, the variation in size being inside of 
rather narrow limits. 
The new type of nozzle is the form in which the spray is in a plane 
inclined at the angle of 45 0 from the plane of the impinging streams, 
but between that and the usual style, having the spray in a plane 90° 
from that of the streams, there is the possibility of any number of inter¬ 
mediate forms that present any desired degree of uniformity in the size 
of the drops. Should a compromise nozzle giving a driving spray with 
greater uniformity than in the existing nozzles be desired, it can readily 
be constructed. The same could be secured by a disproportion between 
the sizes of the two streams, and in this case the coarser portion would 
be at one edge instead of at the center of the fan. This form might be 
desirable for some spot-spraying for scale insects, and it might be desirable 
to have a means of controlling the size of one of the streams. 
