Spraying Devices and Machinery. 183 



are often jointed ; the cans also differ much from each other. 

 The water may be broken up into fine drops by means of a 

 perforated disk, or rose, which covers the outer opening of the 

 spout, the size of the drops varying with the size of holes in the 

 rose. Watering-cans are used advantageously only on very low- 

 growing plants, as the liquid leaves the spout by the force of 

 gravity, and not by pressure applied by the operator. Very 

 thorough applications can be made by means of these cans, but 

 they are wasteful of materials. 



Small hand pumps, commonly called syringes, came into use 

 at an early day. They were very simple in construction, and 

 were at first used almost entirely 

 for throwing clear water upon r w ^*<*f 



cultivated plants. They con- 

 sisted practically of nothing but 

 a tube in which a piston and 

 piston-rod could play. The water 

 was thrown out of the same ori- 

 fice through which it entered. 

 Such a contrivance admitted of 

 considerable variation, and sev- 

 eral styles have been described 

 in very early publications. 



A more complicated form of 

 syringe includes those which are 

 supplied with valves, generally 

 two (Fig. 3). In such syringes 

 the liquid does not leave the cyl- 

 inder through the same orifice 

 at which it entered, but it passes 

 out through another. These orifices are each supplied with a 

 valve which allows of the free passage of water in the desired 

 direction, but prevents its return. The earlier forms of these 

 syringes were made principally by the English, and several more 

 or less modified forms have been described. The principal ones 

 appear to have been Read's, 1 Macdougal's, 2 Warner's, 8 Johnston's 

 portable garden engine, 4 and Siebe's universal garden syringe. 5 



FIG. 3. Small hand syringe having 

 separate inlet and outlet orifices. 



1 " Loud. Ency. of Card." 1878, 546. 



2 <;<tr<l. Md(j. Vol. vi. 305. 



3 Ibid. Vol. viii. 353. 



4 "Loud. Ency. of Gard." 1878, 547. 

 Ibid. loc. cit. 



