208 REPOET 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 



like, with a short slit,/, in the middle, while to each side of it the front 

 edge is bent np ward, more steeply at the center but less and less to- 

 wards the outer angles where the common level of the rest of the i)late 

 is attained and beyond which the margins of the plate roll up. In 

 case the water escapes through the central slit badly it may be bridged 

 over by a drop of solder on its back. 



The third form, Plate XX, Fig. 1, by which similar results have been 

 obtained, is the most satisfactory. In it there are no corners, the front 

 edge, /, being rounded and moderately elevated to an angle approximat- 

 ing 350, but more or less variable with the pitch of tbe impingeut solid 

 jet. Although the upturned sides, lih^ somewhat condeuse the outer mar- 

 gins of the spray thus made, they are thrown as far as the central part 

 because of their encountering less resistance, for the forward margin 

 toward the middle retards more and deflects the fluid strongly toward 

 the sides. 



The form shown in Plate XX, Fig. 2, with a straight slightly upturned 

 front edge, has been used by some in preference to the older style with 

 a plate entirely flat; but while it retards the central portion most it does 

 not spread this part strougly enough and has the fault of retarding also 

 the sides somewhat and deflecting them more than the center, whereby 

 they are thrown less distant and made thinner when they ought in- 

 stead to be condensed slightly in a lateral direction and be not at all 

 imi)eded in front, for the rule to be established for throwing a djflector- 

 spray of equal quality, density, and distance from tbe center to the out 

 side is to hold or deflect the sides somewhat toward the center, and the 

 denser center somewhat toward the sides. 



The nozzle shown in Plate XXI, Fig. 1, was patented by Mr. E. Hol- 

 lings in 1853 (Xo. 9520). The loose ring, 0, surrounding and pivoted, at 

 ss to, the discharge end of the hose pipe, B^ bears the triangular deflector 

 plate, A, and the lever, E^ by which the plate may be tilted up or down. 

 A sjjring, c, tends to elevate the lever and depress the plate, but the 

 thumb can be used in opposition to the spring to alter the pitch of the 

 same at any instant. The same changes can be made more slowly by 

 turning up or down the screw, i>, operating upon the lever through the 

 link, E E; but the screw is especially for the purpose of holding the plate 

 more steadily at the augie desired and without any manual effort. This 

 device without the screw is presented in the descriptive catalogue (p. 

 221, Fig. 159), of Messrs. W. and B. Douglas, of Middletown, Conn., 

 with the statement that '^Fig. 159 shows hose-pipe with our improved 

 sprinkler on it." 



Similar adjustments appear in a more compact and hence more con- 

 venient device patented in 1873 (Xo. 142719) by Mr. Amos Xickerson, 

 of East Somerville, Mass. In Plate XXI, Fig. 2, the flat plate, B, has its 

 lateral margins turned up and is pivoted, at 0, to the hose-pipe, A. The 

 plate is set at the angle desired by the thumb screw, i>, working through 

 its very short lever arm, at s, and against the pipe, A. 



