MACHINES USED IN HORTICULTURE. 



113 



two points of superiority are, a ball-valve, c?, which can never get 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 



Fig. 83. 



Read's garden-syringe. 



washing away insects from wall-trees, and throwing lime-water on 

 gooseberry-bushes and other standards in the open garden, and for 

 watering 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 sunrise. There is also a cap, c, d, 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, 

 requires to be removed, but with the cap c d, it may be kept on. For 

 all small gardens this syringe will serve as a substitute for every other 

 description of watering-engine. 



The barrow-engine, fig. 84, is an oval copper vessel, containing about 

 twenty-six gallons, particularly adapted for large conservatories and 

 forcing-houses. It will pass through a 

 doorway two feet wide, and is so portable 

 that it may be carried up or down stairs 

 by two men. The great power of this 

 engine depends on the air-vessel, indicated 

 by a dotted circular line, in the body of 

 the engine, in which all superfluous force 

 is employed in condensing air, so as to 

 form a reservoir of power ; and in the 

 proximity of the bent fulcrum, a, to the 

 handle or lever, 5, by which the weight c, 

 being brought near to the fulcrum, the 

 power applied at b is proportionably in- 

 creased. In most engines of this kind 

 there is no pneumatic reservoir, and the 

 distance between the weight, c, and the 



Fig. 84. 



Barrow -engine. 



fulcrum, a, is much greater. The construction of the piston-valves, &c., 



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