Page:Popular Science Monthly Volume 90.djvu/733

 Papular Science Monthly

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��Siamese Twins Among Trees — A Remarkable Double Growth

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��HE twin elm trees shown in the ac- companying photograph have been the dehght of the children of Fostoria, Ohio, for almost one hundred years. The con- necting limb between the two trees furnishes an ideal support swing. The trees are ea about one hundred feet hig with a diameter of two feet at the bottom. The con- necting limb is fifteen inches thick. There is a space of about twelve feet between the trees. Evidently the graft- ing, whether done by Nature, accident, or the hand of man, was accomplished when the trees were ver>' young, for it is now impossible to determine to which tree the con- necting limb originally belonged.

��How Chemists Have

Taken the Poison Out

of Common Salt

���AS far as the supply of l\ salt goes there is enough available to last us forever. Michigan alone, it is said, claims to be able to supply the whole world for two thousand years with all the salt it needs. But no matter how plenti- ful salt may be it has the disadvantage of being a poison, for no salt is wholly pure. Thus, if the poison in salt can be elimi- nated vast additional sources will be available.

Scientists have come to the front and have tackled the problem successfully. By adding a solution of just the right amount of [sulphate of soda, the barium or poison in the salt is changed to sul- phate, and with it is removed the pink or brownish color due to iron salts. Thus is made available an unlimited supply of salt, which means more raw material for our chemical industries, because the barium-bearing salt is used fo*. salting hides, for glazing pot- tery and for making ice.

��The trees are twelve feet apart, about one hundred feet high, and are over one hundred years old

��They Aren't Afraid to Go Home in the Dark in Whitewashed London

ALTHOUGH London and the outlying l\ suburbs put out street lights at eight o'clock and appear to say "Good night," and the whole country is swallowed up in darkness, the truth is that the Lon- 1 theaters and night attrac- tions are as popular as ever, Zeppelins or no Zeppelins, ^'hen first the lights were turned out, the night-owls of London had a difficult time feeling their w^ay about. Curbs, stone steps, iron lamp-posts and other formidable objects felt different than they looked. But it wasn't long be- fore the population got its night eyes. Lights were put on perambulators and bull's-eye lamps on moving vehicles, but soon these proved un- necessary-, so expert did the prowlers become.

The photograph shows some Leicester ladies white- washing a step for the bene- fit of the night crowd. Not only are steps whitewashec but projecting cor- nerstones, lamp posts, and many other objects which have a habit of getting in the way,

���Int. Filai Serv.

London Bridge isn't falling down but all London did — until steps and projections were whitewashed

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