238 REPORT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 
The tubing for conducting the blast must of necessity be small and 
diminish its capacity one-half beyond each fork, otherwise the velocity 
will check and some of the powder will be thereby allowed to deposit 
and accumulate inside, occasionally to be thrown ©ut irregularly when 
jarred into the blast. To prevent such accumulations any shaking or 
jarring in the machine will be beneficial, and if the tubes always proceed 
in a somewhat downward course gravitation will assist. 
On this plan is constructed the most practical bellows apparatus yet 
invented for poisoning fields. There is no possibility of moisture im- 
pairing the working of the bellows or reaching the powder in the tight 
can, clogging is less possible, and the powder may be supplied in mini- 
mum quantities beneath several rows. 
It is now necessary to describe some machines embracing the prin- 
ciples above set forth, and also, thereafter, a few devices invented for 
similar purposes by others. 
In Plate XXXIII, Fig. 1, appears one of the bellows, v, recommended 
above, as hung upon the end, c, of a cart or wagon, to be operated by 
the wheel, w, and to blow poison from the can, p, through a system of 
distributing pipes carried on a frame, which has its part, a, supported 
and conveyed by connection with the cart. The cleat of one head of the 
bellows is attached at points, c c, by hanging hooks or clamp-screws or 
otherwise. Between the two projecting ends of the cleats is a spring, 
«, to open the bellows. This may be placed inside, but when situated 
externally can be more easily repaired if necessary. A ratchet, Z, is 
hinged opposite the hind wheel at the attachment, to play upon the 
spokes and operate the bellows by communication of the rod, r, and by 
the reacting spring, s. The blast tube passes through a valve, o, to pre- 
vent the poison powder or fluid from being sucked backed into the bel- 
lows. Beyond this the tube extends through the basal portion of the 
powder-can, after which it connects with the branching system of dis- 
tributing tubes extending to beneath the plants. 
This is a very simple motor arrangement for operating the bellows. 
The same principle may be used with the bellows in other positions, 
and it can be so set with reference to the wheel that its arm, a?, shall 
act as the ratchet, or pawl, upon the spokes, whereby the other parts 
will not be needed. Also for giving or communicating the motion to 
operate the bellows any of the more complex mechanisms used for giv- 
ing reciprocating or oscillating movement may be employed, as, for in- 
stance, those for working pumps in the other machines described in this 
report. 
The reservoir and its device for feeding the poison to the blast may 
be adapted for fluid or for powder poison as desired, the same blowing 
apparatus answering for either. 
A simple bellows blower may be combined with any implement drawn 
in the field, as a plow or cultivator, and so become operated by the 
horse without effort on the part of the plowman, as shown in Plate 
