174 



STATE BOARD OF AGRICULTURE. 



give a 1" tutting edge. This, when ground to an edge, beveled on the 

 inside, gave very good results. 



Three different weights of pneumatic Jiammer were tried, Boyer 

 BB, weight nine pounds, Boyer F, weigiit six and one-half pounds, 

 and Boyer O, weight four and one-half pounds. It was thought at 

 first that only by considerable weight could the rebound be taken np, 

 and hence a heavy hammer was chosen. While this was found verv 

 effective, its weight with that of the length of hose to be lifted made 



tiring. 



Accordingly two lighter weight hammei^s were 



its use verv 



secured and were found to work very well. The lighter hammers give 

 more of a jar to the hand, but this, however, is not enough to interfere 

 with their use. The extra portability and lightness of the smaller sizes 

 make them by far preferable for this work. 



The method of operating the chisel is very simple and one can become 

 skillful with it in an afternoon. It is seen from the cut that the chisel 

 is shaped like a revolver, with the air-throttle valve situated above 

 the hammer and under the control of the thumb. After projecting parts 

 of the w^ouud are hewn away and for this a lather's hatchet is excellent, 

 the opening of the cavity is made with the chisel. This chisel is held 

 firmly against the wood with two hands and the material chipped away. 

 Only solid wood can be cut since splinters or an^- small branches vibrate 

 to and fro with the hammer. 



The chisel should be fastened in the hammer by means of a set screw or 

 a fimi grip chuck in order that it may not drop out. 



It was very soon found that the pneumatic chisel will not replace 

 the hammer and saw and hence the gross work of pruning and cutting 

 must be done as before. The pneumatic tool does do the work of goug- 

 ing out cankers, smoothing stubs flush with the face and oyxining cavi- 

 ties very effectively. In short, it does exactly the work of the gouge 

 and the mallet. 



Careful timing of similar jobs shows that after one becomes proficient 

 in the use of the tool, he can do four or five times more work with 

 it than can be done with the mallet and gouge. 



This tool is recommended to tree surgeons, park boards and city 

 foresters doing tree surgery work and to fruit growers ^\ith large 

 acreages. 



The equi]uuent can most economically be made a ])art of the spraying 

 outfit, by ]>lacing the air pump on this outfit and slinging the tank 

 undornoath the trucks, or setling it uiiright beside the spray tank. 



The ntlings required to make up the y)ressure system ccuisist of the 

 check valve and T>iiiing between the pump and the tank, the hose con- 

 nections, cut-off valve and gauge between the hose and the tank. Park 

 boards buying new spray equipments can save time and secure better 



