284 REPORT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 
chiefly of interest on account of the features of their distributing pipes, 
support, means of conveyance, or other accessories. 
One of the oldest devices in our country for throwing liquid poison is 
a machine thus described by Professor Eiley: 
" The Johnson Spray Machine. — This sprinkler, invented by Judg* 
Jehu W. Johnson, of Columbus, Tex. (patents No. 145571, December 
1G, 1873, and No. 145572, of the same date), is not only the oldest one 
on record for the application of liquid poison on a large scale, but pro- 
duces the spray in a novel and peculiar manner. 
"The accompanying sketch, [Plate LIII] represents tb is machine in operation. It 
will be seen therefrom that it consists of a tank placed upon a two- wheeled cart. 
The pump secured to the top of the tank is a common double-acting force pump, and 
with the discharge-pipe is connected a transverse pipe. These parts need no further 
description, and nothing new or peculiar is claimed for them. The claim for the sec- 
ond patent mentioned above is based upon the addition of a self-acting pitman, the 
arrangement of which can be seen in the sketch, and which is more fully illustrated 
[at Plate LIV, Figs. 1 and 2]. The letter A represents the tank, B the platform of the 
cart, which is provided with the two wheels, C. These are much smaller than ordi- 
nary cart-wheels, in order to give the required number of revolutions necessary to the 
successful operation of the pump. In order to place the cart-bed at such an elevation 
as to pass over the rows of plants, it is raised by means of vertical bars, as will be seen 
in the sketch. One of the wheels, C, has a crank-pin, c, attached to it, at a suitable 
distance from the center, and to this crank-pin is attached the lower end of a pitman, 
the upper end of which is attached to the pump-lever, G. The discharge-pipe of the 
pomp is provided with a valve to regulate the flow of the liquid. With the trans- 
verse pipe before mentioned are connected, by means of screw-joints, branch-pipes, K, 
which in the sketch and in the diagram are five in number. 
" These branch pipes are made of cast metal, and on their inner surface, at the lower 
end, grooves / are formed, either during the process of casting or by planiug or cut- 
ting them out afterwards. In the lower end of these branch-pipes a plug made of rub- 
ber or cork is inserted, and a rod extends from the plug to the upper end of the tube 
k, where it engages with a nut by which the plug may be tightened or loosened. It 
will be seen that the liquid passing through this pipe must escape by way of the 
grooves and assume the form of spray, and that by tightening or loosening the plug 
the size of the grooves is increased or diminished. 
" This machine makes a remarkably fine spray, but it possesses the same disadvant age 
as those already mentioned, namely, the ease with which the nozzles clog, notwith- 
standing the receiving-pipe of the pump is provided with a strainer. This I found te 
be a serious drawback, requiring frequent stopping of the driver and his dismounting 
to remove, cleanse, and readjust the plugs. The addition of the self-acting pitman 
has proved less useful than one would suppose, for Judge Johnson himself writes me 
that ' experience has demonstrated the fact that it is about as easy and far more 
economical to work the pump by band-power than to use the pitman rod.' By dis- 
pensing with it, the tank may be placed on any cart without special construction. 
This machine has been considerably used, but its price ($65 without the cart) is very 
high when compared with that of others here described." 
In this apparatus any suitable force-pump may be used, and no 
special pump features are designated for it, except that a "double -act 
ing" one is recommended. The arrangement of the pipe to bear nozzles 
is essentially the same as may be seen in several later machines, nota 
bly in those of Mr. Jones, Mr. Binkley, and Mr. Goodin, as described 
