196 REPORT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 
ent sizes are offered, and there is a series of face plates substitutive for 
each other, but differing in the sizes and number of perforations. 
Peripheral-roses [divided]. — Mr. J.' C. Melcher, of Black Jack 
Springs, Tex., devised a discoid sprinkler head with a many-punctured 
circumference, patented in 187G (No. 172467). This is now made with a 
lid clamped fast by a screw and removable for cleaning out the interior. 
To Mr. George Yeager, of Flatonia, Tex., was granted in 1871) (No. 
219337) what he regards as an improvement in nozzles of this style, 
which consists in closing the top and base with sheet-metal screw- caps, 
detachable for taking out accumulations from within, while the cap held 
lowest serves to store the heavy sediments. 
A nozzle, Plate XV, Pig. 6, producing this form of spray, is used on 
the Ruhmann sprinkler, but the arrangement for cleaning the interior is 
different, as may be seen in a sectional view, Plate XV, Pig. 7. By 
turning the T-shaped thumb-handle above, a small brush inside is made 
to sweep the inner surface of the punctured rim. It will be seen that 
such sweeping may be kept up constantly by an automatic process 
to be described in chapter XIII. For others see p. 193 and PI. XIY, 
Figs. 1 and 2. 
Rose-combinations. — There are many attempts to combine the rose- 
head and solid-jet pipe in one nozzle. This is done satisfactorily by 
having the rose separable from the pipe by a clutch, or screw coupling, 
a plan which has been already spoken of, but which is illustrated in 
longitudinal section in Plate XV, Fig. 1 representing a nozzle patented 
in 1874 (Xo. 150742) by Messrs. W. Barry and L. H. Prentice, of Chi- 
cago, 111. The circle shows the plug-cock perforated by the cavity of 
the solid-jet pipe that terminates inside of the rose-head Z>, which can 
be separated and screwed upon the nib d, for carrying it while a solid jet 
is used. Compare the clutch-rose, p. 195. 
Several other devices for combining the rose and solid-jet in one noz- 
zle have been found, but they are usually either a little too complex or 
costly to become popular, or else the construction is such as to impair 
either the spray or the solid-jet, or both. 
SLOT-NOZZLES. 
[Plates XVI, XVII, and XVIII.] 
In slot-nozzles the form of the spray is given by a slot or group of 
slots from which it is emitted. The fluid forced from a slot expands 
in a somewhat fan-like shape, and then breaks up into a sheet of spray. 
The best of these are such as have a slightly divergent discharge 
from the side of an eddy-chamber, with or without a deflector lip. The 
examples shown on Plate XVI, Figs. 4 and 5, now seem to be the 
most valuable, though, for broadcast work, such kinds as are shown in 
Figs. 1, 2, and 3 may sometimes be selected. 
To lessen the clogging of small jets adapted to poisoning from be- 
ne;! 1 li. only a single slot can be safely used, its lips should be far apart, 
