Page:Popular Science Monthly Volume 88.djvu/140

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Left-handed Watches for Left Handed People

A WATCH for left-handed people has been invented by a Kalamazoo jeweler, who believes that the left- handed look at things in a "left- handed" fashion. The left-handed watch runs back- ward. The dial is arranged so that the numeral 1 is on the left hand of 12 instead of on the right as in the case of the ordinary watch. The hands also run from right to left instead of in the usual fashion. Mechan- ically, with the exceptions given, the left-handed watch differs very .slightly from the ordinary time-piece.

The inventor constructed the unusual watch for the benefit of his daughter, who is left-handed.

An International Test for Vision

THE International Ophthalmic Con- gress at_ Naples, in order to intro- duce uniformity in methods of measur- ing vision, has adopted the broken ring of Landolt as the best possible in- ternational test for visual acute-

O^^ - ^^ ness. But as no f ^ ^ ^ efforts have been cards with test letters are used, it has had little practical value. However, Dr. Edward Jackson, of Denver, has found that if the broken rings are arranged in a symmetrical group and printed, as here illustrated, on a card that can be turned with any edge uppermost, it constitutes a test independ- ent of a knowledge of letters. The test is placed five meters from the patient. If the direction of the break in the rings is recognized at full distance, full acute- ness of vision is demonstrated. If at four and a half meters, the vision is one- tenth defective, and so on.
 * ^ ^^ made to use it as

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A Pocket Periscope

ONE of the interesting inventions which the war in Eu- rope has stimu- lated is a very small, but none the less service- able, pocket peri- scope. The sol- dier, concealed behind an intrenchment, can quickly at- tach this tiny instrument to the barrel of his rifle, to a pole, or to a trench- digging tool, and can readily observe, by means of the two circular mirrors, the movements of his antagonists in the dis- tance without exposing himself to any tance without exposing himself.

A Trolley for the Stable Lamp

THE problem of carrying an oil 1 a n t e r n while at work in a barn or garage is an old and per- plexing one, but it has been inge- niously solved by an inventor in South Dakota. Instead of depositing the lantern on the floor, on an upturned box, where its light is usually shed to the least advan- tage, he has devised a simple but effective overhead trolley system. A stout wire is extended across the ceiling between braces, and the lantern suspended on a small wheeled truck from it.

Non-Rolling Nursing Bottle

SO many ba- bies these days are bottle- fed that mothers will be interested to know of a new feeding bottle which is flattened at the sides to prevent its rolling over either when baby is feeding or when the mother is washing the bottle. The ounces are scaled upon one side and the rim of the neck is so sloped that the nipple is easily put on.

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