Page:Popular Science Monthly Volume 88.djvu/537

 Popular Science Monthly

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��Woman Invents a Life- Sav- ing Device SIIl^ is an ciuluisiasiic inotorist and drives her car with ease and skill, but just the same she feels a threat deal more secure since she has eciuipped her ma- cliine with a fender of her own invention, for it elimi- nates the dan- ger of injuring some unwary pedestrian. Who is she? Mrs. J. M.Wirt of Omaha. Her feiulcr is en- closed in a small case extending across the front wheels. When not in use it is inconspicuous and does not disfigure the car. In an emergency it springs open like a flash, throwing out a net four feet in front of the wheels. The net is so accuratelv ad-

���The "woman's fender" rolled up. In the oval, it is shown extended after the foot-brake has been depressed to meet an emergency ; for the fender and brake are operated as a unit

justed that it will pick

up an object as small

as a brick ; yet it is strong enough to carry

a weight of two hundred and fifty pounds.

The releasing-trip operates the brake

and fender simultaneouslv.

��Riveting Without Rivets

ELICCTRIC current, reduced to an extremely low voltage but increased in volume to tremendous proportions by

I h e use o f

huge trans- formers, finds an unusual and spectacu- l.ir applica- tion in per- lorming the work that riv- ets are in- tended lo per- form. The chief dislinc- I ion between (he ordinary ri\et and the electric rivet is the differ- ence in time tliat is re- (|uiretl in the I wo opera- tions. The results are

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��Intense electric heat, applied in one spot after another,

welds the steel more firmly and more quickly than

is possible with the use of rivets

��equally successful. Electric riveting re- quires much less time. Riveting, liow- ever, is not the precise word, as welding is the operation that actually takes place.

Two layers of metal to be joined are placed to- gether be- tween the j a w s o f a giant m a - chine. A lex- er is pulled ; electric sparks fly; a spot between the jaws quickly heats to brightness; the two sur- faces melt and flow together. The result is a permanent but practical- ly unnotice- able weld.

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