254 THE APPLE 



well if the rods needed are not over 6 or 8 feet in length. Longer 

 lengths of }-inch iron pipe are hard to handle on account of their 

 weight, and often break off in the threads. Rods of brass pipe are 

 too flexible when made of light tubing, and too heavy when made 

 of strong tubing large enough in diameter to obviate flexibility. 



Extension rods made of bamboo and lined with brass or alumi- 

 num pipe are light, strong, and large enough in diameter to be 

 handled conveniently without unduly tiring the operator. The base 

 and top should be constructed like rod ends, for these thimbles 

 prevent the accidental breaking of the rod at the juncture of the 

 fitting and the lining pipe. Aluminum-lined rods of this type are 

 practically as strong as the brass-lined ones, and are much lighter 

 in weight. Bamboo rods io feet long are usually the most practi- 

 cal, although the 1 2-foot size is not too heavy nor too long for 

 tall trees. The plain thimbled bamboo rods with wired ends are 

 seldom as durable as the other kinds mentioned, for the bamboo 

 is liable to split, and the rod ends are more readily broken off ; the 

 lining pipe and thimbles get loose and turn around in the bamboo 

 support, and there is no satisfactory way to remedy the defect. 



Types of sprayers. Bucket pumps. Pumps of this class are of 

 small capacity, but give a good pressure when properly controlled, 

 and are very useful in greenhouses, conservatories, and small 

 gardens. They cost from $1.75 to $5.00. 



Knapsack pumps. These pumps, which have about the same 

 capacity as the bucket type, are mounted in galvanized-iron or 

 copper tanks. One of the best of these has a compressed-air 

 equipment. They are useful in small vegetable and fruit gardens. 

 The chief objections to them are the cost, — from $5.00 to $12.00, 

 — which is relatively great when the capacity is considered, and 

 the tendency of the tanks to give way, most of the material used 

 in their construction being too thin to stand rough usage. 



Neither the bucket nor the knapsack pumps are adapted for 

 commercial operations. 



Hand, or barrel, pumps. This designation includes all pumps 

 of moderate capacity that are mounted on tanks having a capacity 

 of from 50 to 300 gallons and operated by hand power. The 

 most common is the brass pump mounted on the 50-gallon spray 

 barrel, which has a sufficient capacity to carry two lines of hose. 



