Open main menu

Page:Popular Science Monthly Volume 90.djvu/228

This page needs to be proofread.

21 o

��Popular Science Monthly

���You can't forget your appointments if you write them down on cards and place them in the right compartments in this machine

Do Your Remembering by Electrical Machinery

DO it electrically! The "remindo- graph" is an application of that slogan to the task of remembering. It consists of a wooden cabinet in which there are a number of small pigeon-holes, enough for every quarter hour in the day. On one side of each is the time of the quarter-hour to which the pigeon-hole corresponds, while on the other side is a small electric lamp. At the back of each hole are electric contacts or brushes between which a strip of metal can be placed or taken out at will. This strip can be fitted upon ?, small card, and when such a card is placed in a pigeon-hole an electric battery circuit is closed to corresponding con- nections on what may be called an "alarm clock." Hence when you have an appointment for 2:15, you simply insert one of the cards in the pigeon-hole marked 2:15. As soon as the clock points to 2 :i5 an electric buzzer rings and the lamp lights. This will continue until you take out the card.

���Directing the Fire of a Big Artillery Gun

TO-DAY there is about as much differ- ence between aiming a big gun and aiming a rifle as there is between sailing a superdreadnought and sailing a steam yacht. It was not very long ago, however, that a gun was aimed similarly to a rifle in that the direction in which it was pointed was obtained by sighting along its barrel. But now things are not done that way. The gunners in the European war, for instance, are often far out of sight of what they are shooting at, and the remarkable hits that they make are only explained by the use they make of careful scientific calculations.

To direct the fire of one of the bigger guns, for example, requires that no less than fifteen complicated corrections be made. Each correction requires an average of five adjustments, all of which must first be exactly figured out by those in command. The most important corrections which are made are for the influence of the resistance of the air, the influence of the earth's curvature, and the attraction of gravity on the distance the bullet may be carried. In place of the guess-work of previous times is the use of the most advanced developments in the fields of mathematics, physics and chemistry.

��The machine tells you how much you weigh and shows you what to eat to increase

��A Weighing Machine in a Restaurant Show- Case

THE latest thing in restau- rant fixtures is a weighing machine built directly in a show-case. Doctors are begin- ning to feel that the condition of a person's health is usually shown in his weight. When you lose weight, rest assured that something has gone wrong and that your health has suff^ered as a consequence. The restaurant keeper has a legiti- mate interest in keeping your weight normal. The index of the new scale will indicate your health, and the show- case will tempt your ap- petite, or coax it along if you have none, and will tell you what you ought to eat.

�� �