16 THE IMPORTED ELM LEAF-BEETLE. 
brief account of the skid, mixer, barrel, and pump may be reproduced 
here from our last Annual Report : 
The skid is a simple frame to hold the horizontal barrel from rolling, and consists 
of two pieces (Plate I, Fig. 3 a a) of wood, about the length of the barrel, and in 
section about 3 by 4 inches, joined parallel, apart from each other, by two cleats, b b. 
The inner upper angles may be cut to match the curve of the barrel, as at cc. The 
barcel being placed upon this frame is next to be tilled. 
A good device for mixing the poison thoroughly with the water and for idling the 
barrel is shown in section in Plate I, Fig. 4. It consist of a large funnel that will 
hold a bucketful, and has cylindrical sides, (j g, that rest conformant on the barrel. 
In this is a gauze or finely-perforated diaphragm or septum, rf, and a funnel base, t i 7 
with its spout, j), inserted through the bung. 
By reference to Plate I, Fig. 4, the barrel, fc, will be seen in section, and some of 
its details, together with those of the pump and stirrer, may be noticed. The ful- 
crum, /, has a foot below, screwed to the barrel. Through its top is a pivot, o. on 
which tilts the pump-lever, i i, which is similarly hinged at b to the top of the piston- 
rod. The pump-cylinder, q, is also hung upon trunnions, i, projecting into eyes. In 
this illustration the eyes, e e, have each a neck fitting in a slot cut through the stave 
oppositely from the side of the buug-hole, and beneath the stave is a foot on the eye- 
piece. Its neck is so short that the eye is held down firmly against the top of the 
stave, while the foot is as tight against its under surface. The length of its eye-piece 
is a little less than the diameter of the bung-hole, into which it may be inserted to be 
driven laterally into the slot. The slot is longer than the eye-piece, so the latter may . 
be driven away from the bung-hole for a distance greater than the length of the trun- 
nion pivot. Then the pump being iuserted, until these pivots come opposite the eyes, 
the latter may be driven back as sockets over the pivots, which play in them when the 
pump is worked. To hold these eyes toward the pump and upon the trunnions a 
wedge, v, is driven in the slot beyond each eye-piece. Thus the pump is easily at- 
tached or removed, and its union with the barrel is strong and firm. Perchance it be 
desired that this pump-hole be bunged, the side slots may be wedged to make the 
barrel tight. 
The parts of the pump being hung as described, the hinge, ft, forms a toggle-joint, 
and in its action causes the pump to oscillate on its trunnions, its basal end swinging 
wider than its top, as indicated by the dotted line from x to y. Upon the extremity 
of this swinging end is a loop, //, through which is passed a stirrer-bar, m n, made to 
sweep back and forth in the lower side of the barrel, thus to agitato and mix the sub- 
stances considerably during the operation of the pump, every stroke of the handle 
causing one or two strokes of the stirrer.* 
The method of inserting and extricating the stirrer-bar is as follows : It is raised 
with the pump until the end, », comes opposite the bung-hole, through which the 
bar may be pulled out by the cord, w, which is attached to the end. n, and also prefer- 
ably to the bungs, r and z, as shown. Through the same hole the bar may be inserted. 
This stirring device is the simplest in construction and operation of any yet contrived, 
while working as it does with reference to the concavity of the barrel it is perfectly 
effective. 
The pump is double-acting and very powerful, giving strong pressure 
to disperse the liquid far and finely, for, with the eddy-chamber nozzle 
used, the greater the pressure the finer is the liquid atomized. A block 
or other catch may be fixed on the side of the barrel to fit against the 
skid and prevent the barrel from rocking therein, as might otherwise 
happen, when it is nearly empty, if much power is applied. About one 
pailful of poisoned water was sprayed upon each tree. When only two 
or three trees were to be treated, an aquapult or other bucket-pump 
