The Boy's Book of New Inventions

by Harry E. Maule

It was in cooling that the greatest difficulties were met, and it was this that brought about the great innovations in motor building. The system of cooling the engine with water required much heavy material, such as pipes, pumps, water, water jackets, and radiator.

On account of the general efficiency of a water-cooled engine many builders of aeroplanes stuck to it and developed it to a very high standard. At present many of the prize-winning engines are water cooled, as, for instance, the Wright and Curtiss.

All of these water-cooled engines and several standard air-cooled makes are of the reciprocating type that have stationary cylinders and crankcase while the crankshaft rotates like that of the motor boat.

The famous Curtiss, Anzani, Renault, and others are all engines of this type. They all differ, but all have a high capacity, as we know from the records they have broken. The Anzani and R. E. P. makers, whose motors are air cooled, have used to great advantage the plan of making their motors star-shaped—that is, with the cylinders arranged in a circle around the crankshaft.

This is the shape taken by the famous air-cooled rotary engines of which the much-discussed Gnome is the best known make. In this rotary motor the cylinders and crankcase revolve about the crankshaft which is stationary. Authorities are divided over the Gnome, which has many severe critics as well as many enthusiastic supporters. Its lightness is certainly an advantage. The ordinary Gnome has seven cylinders and develops fifty horsepower while the newest models have fourteen cylinders and develop 100 and 140 horsepower.

A brief description of the motor here will suffice to show the general principle of the rotary engine. The stationary crankshaft is hollow, and through it the gasoline vapour passes from the carbureter at the rear to the cylinders. Of course the inlet valves in the pistons are made to work automatically. The magneto is also placed behind the motor and the segments revolve on the crankcase. Wires extend from the segments to the spark plugs in the cylinders, and revolve with them. The cylinders are turned out of solid steel and the whole engine is conceded by experts to be one of the most wonderfully ingenious ever built. The cylinders and crankcase themselves serve as flywheel, thereby eliminating the dead weight of the usual heavy flywheel in the other types of motors, and the rotation serves to cool the engine perfectly. Again, the rotary motor is light and small, while it develops a tremendously high power. Aviators also claim for it other advantages too technical for consideration here.

Many authorities, in fact, declare that the rotary engine is the aeroplane motor of the future. It is very popular among the French aviators and at present holds a great many speed records. It was with one of these high-power Gnomes that Claude Grahame-White, the English flier, won the Gordon Bennett race at Belmont Park in the fall of 1910, and Weyman again in England in 1911.

While this high state of development in the aeroplane motor has been attained comparatively within a few years, the art of flying has occupied the mind of man since it was described in Greek mythology. The Chinese for thousands of years have used kites and balloons. The ancient Greeks watched the wonderful flights of the birds and invented myths about men who were able to fly. Then Achytes, his mind fired by these stories, invented a device in the form of a wooden dove which was propelled by heated air. Other inventors made devices that were intended to fly, and during the reign of Nero, "Simon the Magician" held the world's first aviation meet in Rome. According to the account, he "rose into the air through the assistance of demons." It further states that St. Peter stopped the action of the demons by a prayer, and that Simon was killed in the resultant fall. Simon made another record that way by being the first man to be killed in an aeronautical accident. Other records show that Baldud, one of the early tribal kings in what later was named England, tried to fly over a city, but fell and was killed. A little later, in the eleventh century, a Benedictine monk made himself a pair of wings, jumped from a high tower and broke his legs. These wings really were rude gliders and the principle remained in the minds of men, even in those days when their chief occupation was war. According to the legends, a man named Oliver of Malmesburg, who lived during the Middle Ages, built himself a glider and soared for 375 feet.