ROTARY BLOWERS. 
229 
hydraulic currents. If positively necessary tbey should be made very 
obtuse and gradual, preferably as long, smooth, regular curves. The 
same caution applies to branches or forks in these blast-pipes. The 
blast may be divided to fork, as indicated in Plate XXVII, Fit;. 4, xss, 
and the discharges may be upward or provided with upward deflectors 
at their terminations. Fol ks, 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 pattern* 
and curves may be employed, such as are shown in Plate XIX, Figs. 1, 
2, and o, 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 application is illustrated in machines presented 
in Plate XXVII, Figs. 4 and ~),gs. Thus the single blast discharged be 
tween a pair of rows is divided and spread laterally and upwards to 
supply both the rows. By bending the wings of such deflectors or set- 
ting them at various angles the discharge can be directed down or up, 
or wherever 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 he irs a small gear or pulley .\ to 1 inch in diameter, 
driven from a gear or band wheel having six t imes the diameter, ami 
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 separately noticed. In 
Plate XXVIII, Fig. 1, o is the crank, c 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, dri, sucking at a, and discharg- 
ing through the tangential exit spout, St, upon which is the powder-can, 
pc, instead of a hopper, and having a hanging base, fr, adjustable in 
the spout, A'.v, by the screws, ft, as desciibed. In Fig. 3 is a plain sec- 
tion having like parts similarly indicated, the distinctive feature be- 
ing that the bottomless po w d e r - c a n , pcx : is mounted upon the drum, in 
which the shelf, b, hangs. This plan of construction is embodied in 
the machine of Plate XXVII, 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 
