This "X-Y position indicator for a display system" is better known as the world's first computer mouse invented by Douglas Engelbart. With a shell built from wood, two wheels tracked the movements of the device. It's too bad the patent expired in 1987 before the real money came rolling in.
Other interesting factoid: Engelbart's team nicknamed the device a "mouse" and the on-screen cursor a "bug." One term took off while the other died a gruesome, lonely death. Hit the jump for a bonus pic. [wiki via techeblog]