Page:Popular Science Monthly Volume 88.djvu/538

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��Popular Science Monthly

��Motor-Testing Up To Date

THE accompanying illustrations show two methods which are used in two motor-car factories for testing every chassis before it is turned over to the sales department for ultimate sale to the consumer.

In one method of scientific test- ing the semi-finished chassis with the motor in place is fastened beneath great air-fans. The rear wheels are belted to the fans which act as a brake. The motor is tested in this way. The power it devel- ops is used to test the re- mainder of the chassis. Three frames at a time are tested. Following this test, tires are put on the cars and they are given a road trial.

In another method of testing, the rear wheels of

��The Dog as a Carrier of Disease

THE dog in the country is a useful and pleasant adjunct to the farm if he is properly controlled and cared for, but when neglected, may readily become a carrier of disease to stock, in addition to gaining opportvmity to kill sheep and destroy gardens and other property. Dog ordinances, as a general rule, have been intended chiefly to curb the dog's power

����Testing the horsepower of an automobile before leaving the shop. With the aid of meters set up on a support in front of the apparatus, the actual horse- power delivered to the rear wheels is read directly

��the completed chassis are placed on large rollers set beneath the floor of the test house, and these rollers are geared to electric d)'namometers which impose a load on both the motor and the trans- mission elements. \\'ith the aid of me- ters, set up on a standard in front of the operator, readings of the actual horse- power delivered to the rear wheels can be taken directly. Incidentally, it is in- teresting to note that the power devel- oped is not wasted but is used to light the test house.

��The testing plant of a modern automobile factory

of doing harm by attacking, biting, killing or running sheep or stock. The part that he plays as a carrier of diseases to animals only recently has been recognized according to the zoologists of the Depart- ment of Agriculture, who be- lieve that when this is better understood, rural ordinances and laws which lessen this danger will gain the support of the community.

Of the diseases carried to stock by dogs, the foot-and- mouth disease is probably of the greatest interest at this time. In this case the dog acts as a me- chanical carrier of infection. The dog which runs across an infected farm may easily carry in the dirt on his feet the virus of this most contagious of animal diseases to other farms, and thus spread the disease to the neighboring herds.

There are, however, many other mal- adies in the spread of which the dog takes an active part. Rabies, hydatid, ringworm, favus, double-pored tape- worm, roundworm, and tongueworm are often conveyed to human beings in this

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