ROTARY BLOWERS. 229 



hydraulic currents. If positively necessary they should be made very 

 obtuse and gradual, preferably as long, smooth, regular curves. The 

 same caution ai^plies to branches or forks in these blast-i)ipes. The 

 blast may be divided to fork, as indicated in Plate XXVII, Fijj. 4, xss, 

 and the discharges may be ui)ward. or provided with upward deflectors 

 at their terminations. Forks, if long, should be flexible, yielding so as 

 not to hang too badly on the plants ; but the double deflectors can 

 be very short and rigid. The deflectors may also be used to spread 

 direct or divide the single blast. For these purposes various patterns 

 and curves may be employed, such as are shown in Plate XIX, Figs. 1, 

 2, and 3, described above. The forms in Plate XIX, Figs. 1 and 2, 

 are the most satisfactory I have been able to devise for use on these 

 rotary blowers. Their api3lication is illustrated in machines presented 

 in Plate XXYII, Figs. 4 and 5^gs. Thus the single blast discharged be- 

 tween a pair of rows is divid'ed and spread laterally and upwards to 

 supply both the rows. By bending the wings of such deflectors or set- 

 ting tl\em at various angles the discharge can be directed down or up, 

 or wherev^er desired. It is also important that the deflecting surfaces 

 be kept bright. 



Light fans may be made of sheet metal soldered to a wire reel or sim- 

 ply to an axle having each end hung in a strip of metal attached across 

 the head. The axle bears a small gear or pulley ^ to 1 inch in diameter, 

 driven from a gear or band wheel having six times the diameter, and 

 bearing a small hand-crank three inches long, by which the necessary 

 velocity in small hand machines is easily attained. Thus the fans are 

 easily operated, requiring only the slightest amount of force if all the 

 surfaces work smoothly and loosely as they ought. These parts are 

 indicated in some of the figures which may be separa,tely noticed. In 

 Plate XXYIII, Fig. 1, o is the crank, e the drive-gear, and n its small 

 driven gear upon the fan-axis, which is hung in the support, r. The 

 radiating fans whirl in the drum or case, dd, sucking at a, and discharg- 

 ing through the tangential exit spout, ss, upon which is the powder-can, 

 pc, instead of a hopper, and having a hanging base, &, adjustable m 

 the spout, ss, by the screws, tt, as described. In Fig. 3 is a phdu sec- 

 tion having like parts similarly indicated, the distinctive feature be- 

 ing that the bottomless ijowder-can, pcx, is mounted upon the drum, in 

 which the shelf, &, hangs. This plan of construction is embodied in 

 the machine of Plate XXYII, Fig. 5. It works well and may yet super- 

 cede the plan of joining the powder holders with the pipes. The latter 

 machine is suspended against the side by a loop over the shoulder. 

 The gearing is the. same as that noticed above, but the spout is directed 

 downward to the ground and backward, bearing a double deflector to 

 supply the two rows between which the bearer walks. The pipe may 

 hang or drag and can be of any suitable length. When the person is 

 walking the poison may generally be freed very close behind him, as 

 the blast of the machine should direct it somewhat backward and with 



