Device of Dr. Jacobus
In the same work by Gaspar Schott from which an account of the preceding device is obtained he gives an account of the device of Dr. Jacobus.
Dr. Jacobus's scheme is illustrated by the following figure:
It will be observed that the above figure shows a string of iron balls "A" suspended on a grooved wheel "E" on an axle "C" between two uprights "FF". At "H" lies a large lodestone, which is to attract the balls at "D" and was expected by the inventor to cause the wheel to rotate.