Page:Popular Science Monthly Volume 91.djvu/407

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Popular Science Monthly

��An Efficient Hen Is an Investment Paying 150 Per Cent

INTENT upon an increase in the egg and poultry production in Texas, the de- partment of poultry husbandry in the State Agricultural and Mechan- ical College has prepared a photograph which visual- izes for the farmers, and the city man as well, the wonderful earning possi- bilities of the hen as an in- dustrial ma- chine.

Considered industrially, says the department, the hen is a very efficient machine. From seventy pounds of feed costing about three cents per pound, a good hen will produce in the course of a year from 150 to 160 eggs, which are worth just now about three or four cents each.

���From seventy pounds of poultry food a good hen will produce about one hundred and fifty eggs in the course of a year

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��French lines. They were notably success- ful, and attracted world-wide attention. Since that time numbers of trench-diggers have been employed on the battlefield, until now they are to be seen everywhere.. In an eight-hour day one digger can excavate trenches sufficient to hold an army of seven thousand men. It would take the seven t h ousand troops two days to dig the same length of trenches. Of course, the dig- ger makes bet^ ter progress where the earth is free from large stones and obstructions. The accom- panying photograph shows a digger of the kind generally used. Steel buckets at- tached to an endless chain dig the dirt and carry it up a side-chute where the dirt is dumped. The matting of leaves and bran- ches which covers the machine is put there to deceive enemy airmen.

��An Army Burrows Itself in the Ground by Machinery

MECHANICAL trench-diggers are not new, either in this country or in Europe. About two years ago the first machines to reach Europe were put to work excavating trenches behind the

���A modern trench-digging machine excavating a French soil. The machine top is decorated with

��Checking Insect Ravages with Armies of Enemy Insects

ONE hundred million dollars are lost to the United States every year due to

the ravages of insects in crops. Half these

insects were imported.

Though insecticides are useful, they are not effective under all con- ditions. The most satisfac- tory results have been ob- tained by introducing other insects which feed upon the undesirable foreign pests.

The threatened destruc- tion of California's orange groves was arrested by the importation from Australia of a certain species of lady- bird. The tiny workers were shipped in tin boxes, placed on ice. Once released in the atmosphere of southern Cali- fornia, they set about their appointed duty with such avidity and multiplied so rapidly that the pests were

trench on virtually wiped out in a very

camouflage short time.

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