This is the receiver for the mechanical square-root calculator. The equally-spaced bars are marked, Right to Left, 1, 2, 3, 4, 5 and 6. Fractions .2, .4, .6, .8 are marked between each whole value, If you launch a ball from, x, it will hit the y bar: x y 1 1 4 2 9 3 16 4 25 5 36 6 That's the integers [1..6] as results from balls launched from the squares of the first 6 non-zero integers.

Put a ball on 2 and it will strike at about 1.4, just where you'd expect. A ball from 10 will land just past 3.2

OBVIOUSLY the spacing of the metal bars and the height difference between them and the level end of the inclined plane are important, as is the angle and spacing of the inclined plane.

It causes me to want to make something that calculates the length of the hypotenuse of a right triangle...