Page:Popular Science Monthly Volume 89.djvu/180

This page needs to be proofread.


100

��Popular Science Monthly

��Modern Methods for Exterminating the Mosquito Pest

NEXT to draining, the best way to atjolish mosquito breeding places is to treat the water so as to kill the mosquito larvae. While many sub- stances have been tried for this purpose, nothing has given such good results as petroleum, according to experts of the United States Department of Agricul- ture. Common kerosene of low grade is most satisfactory as regards efficiency and price.

It has been found that spraying with a portable pump is the best way to use the oil. Small ponds, however, can be sprinkled out of an ordinary watering- pot with a hose nozzle, or for that matter pouring it out of a dipper or cup will be satisfactory. In larger ponds pumps with a straight nozzle may be used. A straight stream will sink and then rise and the oil will spread until the whole surface of the water can be covered without waste.

In choosing the grade of oil to be used two factors must be considered; it should spread rapidly and should not evaporate too r|uickly. Heavier grades of oil will cling together in spots and the coating will be necessarily thick. It has been found that one ounce of kerosene is sufficient to cover fifteen square feet of surface, and in the absence of wind, such a film will remain persistent for ten days. Kven after the iridescent scum apparently disappears there is still an odor of kerosene about the water. A mixture of crude oil and ki>rosenc has been found to be effective in killing mosquito larvae. It has one advantage over pure kerosene in that it does not evaporate so cjuickly.

S])ecial attention should be paid id little pockets of water that form around the edges of ponds, for it is in sucli places where the water is not disturl)ed l)y wind or otherwise that the larvai' breed in greatest numbers. Larvae do not breed in open stretches of water where the surface is rippled by the wind.

In the fight against the mosquito in Panama, the governiuenl experts found that a larvicide coiuposed of carbolic acid, rosin and caustic soda was very effective and lliousands of gallons ol il were used.

��Threshing by Night Under Electric Light

THE farmer like the city man does not allow daylight to put a quietus on work. On the other hand he labors into the night just as assiduously as the city man, and makes hay not only while the sun shines on this side of the earth, but while the sun shines on the other side, too. With the aid of a new portable generator recently placed on the market he can do his threshing at night, and do it with a degree of thoroughness not excelled in the brightest sunlight.

The dynamo is drawn up beside the thresher and is driv^en by a belt from the threshing machine. The apparatus is sufficiently powerful to light at least one arc light, which throws a brilliant white light on the field of operations. When the farmer finds the spring thawing season suddenly thrust upon him and the ground ready to be plowed he can work far into the night with the aid of the same portable generator. It sup]5lies light for two projecting lamps, one in front to light the way, and the other in the rear to show the plowed area.

��Uncle Sam Says Miraculous Wheats Are an Old Delusion

THE notion that tiicre is a wonderful wheat which will make the fortune of anyone who plants it seems to be al- most as old as agriculture itself. In this country, at least, such an assertion was made for the so-called Jerusalem wheat as early as 1807, and, imder the name of Alaska wheat, this identical variety is still being pushed upon the unwary at exorbitant prices for seed. Almost equally exaggerated claims are made for the Stoner variety, but this particular wheat has not such a long history.

Recanse of the many attempts that ]\,\\v been made by promoters to foist these wheats, under one name or another, upon the farmers of the country, the Deiiartment of Agriculture has made careful tests of their ^•alue. The re- sults of these tests arc saitl to show con- clusively that neither of the wheals ])ossesscs any peculiar (|ualil\' which justifies high jirices for the seed. Many \arielies grown connnercialh' throughout tile counlry ha\'e pr()\'ed to be superior to either the Alaska or the Stoner.

�� �