Popular Science Monthly 



857 



A New Powerful Farm-Tractor 



ONE of the most powerful of the 

 many farm tractors now on the 

 market has recently been ofifered to the 

 public. This new machine is remarkable 

 not only for its great pulling power, but 

 for the ease with which it 

 plows through almost im- 

 passable swamp, marshes 

 and beds of streams. 



The features of construc- 

 tion that permit of success- 

 ful usage under such severe 

 conditions are the double- 

 worm drive and the swivel 

 action of the axles. The 

 four-cylinder develops sixty 

 horsepower, but since this 

 power is directed to both 

 front and rear axles, great 

 tractive ability results. 



fruit growers, which mixes the compo- 

 nent parts of the gas and liberates the 

 fumigating gas in any desired quanti- 

 ties. In the employment of this ma- 

 chine, a tent is placed over the tree 

 which is about to be treated. By 



This four-cylinder tractor develops sixty horsepower, 



which is divided between front and rear axles, affording 



great tractive ability 



Killing Insects with Poisonous Gas 



FRUIT growers of California who 

 have long contended with insect 

 pests are now employing a new method 

 of killing the pests, which is said to 

 be exceedingly efficient. Lender the 

 old system of spraying the trees, the 

 best result that could be obtained un- 

 der the most favorable conditions was 

 the removal of from eighty to eighty- 

 five per cent of the insects. By fumi- 

 gating the fruit trees with hydrocyanic 

 gas, it is said that one hundred per 

 cent results are usually obtained. 



A gas-making machine has been re- 

 cently placed at the disposal of the 



means of markings on the canvas the 

 number of cubic feet occupied by the 

 tree is accurately measured, and the 

 amount of gas to be employed is thus 

 decided. It has been discovered that 

 the strength of the gas mixture to be 

 used depends upon the size and age of 

 the tree. On the average tree, from 

 ten to fifte'en feet in height, a strength 

 of about one ounce of cyanide to one 

 hundred cubic feet of gas is the aver- 

 age dosage. 



The proportion of cyanide, acid and 

 water is adjusted in the machine. The 

 usual proportion is that of equal parts 

 of cyanide and acid, but the proportion 

 of water varies from two to eight 

 ])arts. 



The gas is liberated un- 

 der the tent, and permeates 

 the enclosed space, thus fu- 

 migating every branch and 

 leaf of the infected tree. 

 The gas is held in the tent 

 for al)out an hour, when all 

 llic insects are usually 

 found to have perished. 



The ordinary equipment 

 employed by contractors to 

 fumigate an orchard con- 

 sists of one gas machine, of 

 the type shown in the illus- 



An equipment for fumigating an orchard consists of 

 one gas-machine, about thirty tents and five or six men 



tration, about thirty tents, 

 and a staff of five or six men. 



