2 Different Plans - Roll-a-Ball and Grip Gauge.
The principal is to zigzag a large marble or steel ball from the starting position shown in the photo through the pivoting parallel bars to the base You must manipulate the levers skillfully to avoid inclining the bars too much so that the marble shoots past the projecting catch-end of the next lower bar.
Easy to build, the device consists of 5 flashlight bulbs, a 6 volt lantern battery, a doorbell and a simple switching arrangement. The lower end of the movable hand grip connects to one terminal of the 6 volt battery so as to close the circuit to the various lamps as it makes contact with the stationary lugs.
Four pages ( 3 sheets - front on first sheet, front and back on second and front on third sheet ) B & W photos, illustrations, expanded view and instructional narrative.
My plans are from original source materials such as books, magazines and other publications and the pages are carefully removed.