# Page:Popular Science Monthly Volume 89.djvu/658

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.

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

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

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