REMEDIES AGAINST FOREST INSECTS. 45 



motion of the liquid, which issues iu a funnel-shaped spray through a 

 central outlet in the adjustable cap. The breadth or height, fineness or 

 coarseness of the spray depend on certain details in the proportion of 

 the parts, particularly of the central outlet." 



Fig. 11 shows two styles of this nozzle, which I bave adopted from a 

 host of experimental forms as the best for all ordinary work. At A is 

 shown the typical small-stemmed nozzle, with the screw cap removed 

 to show the inlet orifice d. At B is shown a sectional view of the same 

 again with the cap removed, showing the tangential entrance to the 

 chamber a through the orifice e, which when the cap is inserted coincides 

 with the orifice d. At C is shown a face view of the cap c, which should 

 be countersunk about the orifice of exit on the exterior surface only ; 

 and also an outline drawing of a chamber placed at an angle of 45° 

 with the stem — a form of advantage especially in overhead spraying. 



The stem may be inserted into the discharge-pipe and fastened by 

 wrapping tightly with copper wire, or a more convenient form is made 

 with a female screw of a size to fit a three-eighth inch nipple. The 

 nipple is inserted into the discbarge-pipe and fastened in the ordinary 

 manner, and allows an easy interchange of nozzles of different sizes or 

 patterns. A discharge orifice of about one-sixty-fourth of an inch may 

 be used for a very fine spray ; for coarser and heavier work a one-six- 

 teenth-inch orifice will be j)referable. 



The value of rotating the liquid to break it up into a suitable spray 

 and to prevent clogging, which are the essential features of the Eiley 

 nozzle, has been universally recognized. 



In this country, owing to the fact that this nozzle has not been pat- 

 ented and is not pushed by interested parties as are patented contriv- 

 ances, it has not come into such general use as its merits warrant or 

 as has accompanied the introduction of patented modifications of it in 

 other countries. It is now, however, being quite extensively manufact- 

 ured and offered by the trade, and a number of modifications of this 

 nozzle have appeared in France, which, while adding certain new feat- 

 ures, have not departed from the valuable principle of the typical form, 

 viz : that of the centrifugal motion of the liquid. These nozzles are 

 employed in France, Germany, and other European countries almost 

 to the exclusion of all other forms, and in this country they are also 

 extensively used. More recently a valuable modification has appeared 

 in this country, the Universal Spray Tip, and in l!^ew Zealand a com- 

 pound form is manufactured, known as the New Zealand Triplet, and 

 fashioned after one which I used and described in California in 1887. 



A full description of the important modifications of the Riley nozzle 

 that have appeared m this and in foreign countries is given by me in 

 Insect Life, Vol. I, Nos. 8 and 9, to which the reader is referred for fuller 

 details. 



In this country, these nozzles are manufactured under contract, for 

 dealers, by Thomas Somerville & Sou, Washington, D. C, and by 



