154 MACHINES USED IN HORTICULTURE. 



the baiTow ; it is well suited for carrying heavy subsoil, or stony materials, 

 but is not required in gardens. For general purposes, a middle-sized bar- 

 row, between the dung barrow and the mould barrow, like that of which 

 we have given a figure, is sufiicient. 



439. Rollers are essential in even the smallest garden, for compressing and 

 smoothing gravel walks and lawns. They are formed of solid cylinders of 

 stone, or hollow cylinders of cast iron, and a very convenient width is four 

 feet. Cast iron rollers are always easiest to draw, from the greater diameter 

 of the cylinder. The operation of rolling is most effective after the soil or 



Fig. 80. Read's garden syringe. 



gravel has been softened by recent rains, but is at the same time 

 sufficiently dry on the surface not to adhere to the roller. 



440. The watering engines used in gardens are the syringe, 

 the hand-engine, and the barrow-engine. There are several 

 kinds of syringe, but the best at present in use is decidedly 

 that of Read (fig. 80). Its two points of superiority are, 

 a ball- valve, which can never go out of repair, and an 

 air-tube, e, which allows the air above the piston to escape 

 during the operation of drawing in water, by which means 

 the labour of syringing is greatly diminished. There is a cap, 

 a, for washing away insects from wall-trees, and throwing lime- 

 water on gooseberry bushes and other standards in the open 

 garden, and for water-pines overhead ; a cap, &, for sprinkling 

 plants in forcing-houses, which throws the fluid in a light and 

 gentle moisture almost like dew, and which is also used for 

 washing the leaves of trees and plants when frost-nipped in the 

 cold nights that often prevail during the spring, and which 

 operation should, of course, be performed before sun-rise. There 

 is also a cap, c, which is used when great force is required, 

 more particularly in washing trees against walls ; and this cap 

 is also used in dwelling-houses for extinguishing fires. Trees 

 against walls are frequently covered with netting, and when it 

 becomes necessary to syringe these, the netting, when the cap, 

 6, is used, requhes to be removed, but with the cap, c, it may 

 be kept on. For all small gardens this syringe will serve as a 

 substitute for every other description of watering engine. Read s 

 pneumatic engine (figs. 81 and 82), the former to a scale of 

 in. to 1 ft., differs from Read's hand-syringe in effect, by forcing 

 out the water in one continuous stream, and thus at once com- 

 bining the character of a syringe and of an engine. By this 

 engine, a volume of air is compressed to an indefinite extent, by 

 the working of the piston for forcing out the water, and without 



any sensible increase of labour to the operator. The manner in g. 8i. Read's 

 which this is effected wiU be understood by the section, fig. 82, P^^^<^i}^ 



... . - , , -, . -r. -.» . I hand-engmej 



m which a is the piston and cylinder, as m Read s syringe ; 6, 



