Page:Popular Science Monthly Volume 89.djvu/658

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Measuring the Horsepower of That Baby of Yours

DR. JOHN R. MURLIN, of Cornell University Medical College, has devised an apparatus which causes a baby to record its own horsepower. Horsepower is used in this sense merely as the expression of a unit of energy. Dr. Murlin devised this apparatus for use in the study of the energy requirement of the new-born child.

A baby unconsciously writes the story of its energy by means of its pulse and its breathing. A small cuff is attached to the left leg of the infant above the knee. From this cuff a tube leads to a glass connection, passing through the wall of the incubator and finally to a T-tube on the top of the incubator. One limb of this tube passes to an air-pump and the other to another T-tube. To the second T-tube a mercury pressure gage (manometer) is connected by one limb and a pressure-bottle to the other. From this bottle a transmission-tube leads to a recording drum. Thus with each pulse the baby makes a record.

Oddly enough, the fattest baby produced the smallest degree of horsepower. While sleeping the babies produced an average of .004 of a horsepower. It was determined that the normal heat productionof recently fed, sleeping babies between two months and one year of age is .09 horsepower.

��A Magnet Made from Two Discarded Cannons

PROBABLY the largest and strongest magnet in I lie world is at \\'iliett's Point, X. Y. It was made by accident. The comman- der of the post happened to see two old fifteen-inch Dahlgren gun.5 lying uiuised side by side on the dock. He conceived of the idea of con- \erting them into a magnet of enormous power by wind- ing submarine cable around them.

The magnet, which stands

about ten feet from the

ground, is eighteen feet long,

and has eight miles of cable

around the upper part of the

guns. It takes a force of

twenty-five thousand pounds to pull off

the armature. A crowbar applied to

the magnet requires the combined force

o{ four strong men to tear it away.

���Two 15-inch Civil War cannon converted into an electromagnet wliich is so power- ful that it takes a force of twenty-five thousand pounds to pull off the armature

�� �