SLOT-NOZZLES. 
19? 
and any reduction of the discharge capacity should be made by short- 
ening the lips rather than by narrowing their interspace or slot. Dimin- 
ishing by this rule the smallest slot attainable becomes only as loug as 
it is wide, and loses the slot character. 
If coarse slots do not make the spray fine enough, the latter may be 
thinned by adding a very short deflector lip, for it will be seen farther 
on that the principles of deflection and rotation may be advantageously 
superadded upon or combined with the slot in almost all cases. 
If the many-punctured principle is the worst for small jets, the slot 
principle cannot rank much better for this purpose. We have seen that 
to get a spray of very limited size the slot must be made either so nar- 
row as to clog too much or must be shortened until it is about as long- 
as wide, or the spray is not thrown thin and broad enough without add- 
ing a deflector. This suggests the substitution of the deflector in place 
of the slot. The round-hole deflector certainly ranks higher than the 
slot-nozzle for small jets, but it in turn is superseded for this purpose 
by the eddy-jets, as we shall see further on. 
The slot answers for heavy broadcast sprinkling; but also in this 
work, if it has aperture enough uot to clog, the spray will be too coarse 
for administering poison homogeneously, and if narrow enough to give 
sufficient fineness it will choke too much. Yet by certain Improvements 
these defects may to some extent be remedied. The slots may be cut 
in various combinations, and several slotted rose-heads 'have been pat- 
ented. A number of straight slots may be arranged as parallels, or as 
whorls of radials, or diagonals; also, curved slots may be grouped con- 
centrically, or as whorls of radials, or diagonal curves or spirals. The 
only object in multiplying the number of slots in one and the same noz- 
zle is to increase the volume to make large sprays without diminishing 
the quality by making a smaller number of slots coarser ; for the liner 
the slot the finer the spray and the less its volume. Where force is ap- 
plied groups of slots are preferable to the groups of smaller perforations 
of the many-punctured nozzles of the preceding group, and when rota- 
tion of the liquid is introduced in many-slotted chambers the cuts should 
be preferably concentric and thus parallel with the rotary current. 
The slits may be cut on ends or sides of pipes, heads or nose-pieces 
of all forms, each end-form like each slot-pattern having its own pecu- 
liar adaptation ; but the slotted surface should generally be in some 
way curved with cylindrical, conical, or spheroid contour to emit the 
spray in a radiating manner, and thus spread it more widely, or collid- 
ing slot*jets can be used. A rounded end should preferably have an 
internal cavity of capacity and form suited to adapt it for a rotation- 
chamber, since the rotary principle may also be introduced as an im- 
provement in nozzles of this group. 
Selecting with reference to these principles, and also for the purpose 
of adopting a nozzle- end of such form that it can be cut with slots of 
any form or grouping that may be made on either sides or ends, and 
