INSECTS INJURIOUS TO SHADE TREES. 89 



pump need not be of large capacity, for it is not expected 

 to throw large quantities of water in a short time; but it 

 should have a large air chamber and should be capable of 

 -applying a maximum amount of pressure with a minimum 

 amount of work. The stroke need not be long, but the lever 

 should be long and strong, and the pump should be hori- 

 zontal, not vertical. An up and down stroke is tiresome and 

 cannot be long maintained without losing in strength; a 

 horizontal stroke may be aided by the weight of the body, 

 and both or either hand and arm may be used. All these 

 matters are important, because upon the amount and uni- 

 fnniiitv of the pressure the thoroughness of the 



, . , ** , . The pump. 



work depends in large measure. The working 

 parts of the pump should be of brass, the valves and packing 

 should be of metal and the valve seats should be readily ac- 

 cessible. Such a piece of machinery will stand every rea- 

 - -liable strain that is likely to be put upon it, and will come 

 "in at the end of the season almost as good as it was at the 

 beginning. It will never be worked to its limit in tree spray- 

 ing, and with reasonable care will last many years without 

 much expense. Such a pump is never cheap at first cost, 

 but is a cheap pump in the long run. Of course no piece 

 of apparatus is entirely fool proof, and that fact should be 

 kept in mind when hiring men to work it. 



There should be two lines of % hose, best quality, each 

 100 feet in length, and there should be 6 or 8 foot gas pipe 

 spray rods, at the ends of which the nozzles should be fixed. 

 There should be a shut-off at the base of each spray-rod and 

 one rod should have a solid jet nozzle for reaching the tops 

 of trees, while the other should have an adjustable or bor- 

 deaux nozzle for making a spray to reach the lower branches. 



As to the poison to be used, there is nothing better than 

 arsenate of lead for all leaf-feeding insects, and for choice I 

 prefer the dry, powdered form because of its greater con- 

 venience in handling and because of its keeping Arsenatc 

 qualities. If the paste form is used, it should of lead> 

 bo purchased on guarantee of percentage of arsenic, for it 

 runs all the way from 12 per cent, to 20 per cent., and may 



