The English, the invention of an Australian named Brennan, had its first form in a model, a small car on which the gyroscopes rotated at the enormous speed of seventy-five hundred revolutions per minute. They were hung in special bearings and rotated in a partial vacuum, the friction being so slight that the wheels would continue to revolve and give stability to the car for a considerable time after the power was shut off. Also, in such a case, supports at the side kept the car from overturning. This model showed itself capable of traveling at high speed on a single rail, rounding sharp curves and even traversing with ease a wire cable hung in the air. In 1909 a car was tried fourteen feet long and ten feet wide, capable of carrying forty passengers. The gyroscopes in this, moved by a gasoline engine, revolved in a vacuum at a speed of three thousand rotations a minute. They were three and a half feet in diameter and weighed together one and a half tons. With a full load of passengers, this car sped easily around a circular rail two hundred and twenty yards long and proved that it could not be upset, since when all the passengers crowded to one side the car remained firmly erect, the gyroscopes lifting it on the weighted sides. It is claimed that in the monorail system so equipped with the gyroscope, a speed of more than a hundred miles an hour is possible with perfect safety. [Illustration: A MONORAIL GYROSCOPE CAR] The German invention, displayed by Herr Schorl, a capitalist of Berlin, is in many respects like the English one. The experimental car was eighteen feet long and four feet wide, the gyroscopic flywheels being very light, weighing but a hundred and twenty-five pounds each, while their speed of rotation was eight thousand per minute. The same success was attained as in the English experiments, and there seems to be a successful future before this very interesting vehicle of travel. There is also another type of monorail of overhead construction, the wheels running on the rail from which the car hangs. The fundamental principle of the gyroscope lies in the resistance which a flywheel in rapid motion presents to any change of direction in the axis of rotation.