Page:Popular Science Monthly Volume 88.djvu/885

 Popular Science Monthly

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��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.

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