222 REPORT 4, UKITED STATES ENTOMOLOGICAL COMMISSION. 



Yet these in turn are surpassed hy the blowers treated in the following 

 chapter. 



EoTATED ORIFICES. — If a tube supplied with water, even without 

 water pressure, be whirled, the centrifugal force will cause the water to 

 flow through it and fly off from its distal end in the form of a circular 

 broadcast spray. The devices I have contrived to test the possibility 

 of utilizing this principle show that it can be used for coarse sprinkling 

 and that sprays may thus be easily thrown 25 or 30 feet wide. 



Pronged reels. — ^When liquid is allowed to flow onto the axis of a 

 group of radiating, whirling prongs of wire or other material, a centrifugal 

 action appears in the fluid following the prongs causing it to fly off from 

 their extremities, thus producing a circular shower. As such reels and 

 stiff brushes grade into each other, they may be noticed further under the 

 following paragraph. 



Brush poison-throwers. — If a brush of any sort be supplied with 

 fluid or dry poison, and its bristles be sprung, their elastic recoil im- 

 parts a centrifugal force to the material which will be thrown in a spray. 

 Also if a cylindriform brush, or one of any other shape, be rotated rap- 

 idly, the centrifugal force will disperse the poison fed to it, whether the 

 bristles be sprung or not. Utilizing these principles some machines 

 have been constructed which promise much, and will be described here- 

 after. The following kinds of fiber have been tested to get their rela- 

 tive values in brushes for this purpose: 1, broom corn; 2, stout bristles; 

 3, tampico; 4, so-called sea-root; 5, spintered woods; 6, split goose 

 quills; 7, whalebone; 8, coarse hemp; 9, wire. 



Any of these answer for sprinkling or powdering from above, and, 

 where plants are very low, for poisoning from beneath ; but where poison 

 is to be throvrn from below upwards into plants as tall as cotton, the 

 more stiff* and longer fibers answer best. Broom-corn x)roves the most 

 satisfactory for throwing powder on account of its length, strength, 

 elasticity, and cheapness. In these brushes the straws or bristles should 

 not be inserted densely, but ought to have plenty of room to flex and 

 recoil freely. A very good size for the brush is 7 inches diameter and 

 4 or 5 inches in length. 



Very s'-out hog-bristles work well, but are almost too expensive. They 

 throw a finer spray than broom-corn, but not so far. Also the moisture 

 destroys their stiffness and elasticity more than that of the corn. 



Tampico brushes throw powder and liquid nicely, but the fiber is not 

 durable enough. It loses strength and breaks off or wears out too soon. 



The so-called sea-root brushes work only tolerably well. The mate- 

 rial is as strong as broom-corn and somewhat similar in appearance, but 

 its fiber has not the length, stiffness, and elasticity of the latter. 



Quills from geese or other fowls will also answer. They should be 

 split in halves, or thirds, or quarters, and inserted with shellacked pegs 

 into a cylindrical wooden core or hub. The quills soften greatlj', from 

 being wet, and hence lose their stiffness and straightness very soon if 



