It's the device used to make the 'crack' for plumber dolls!

Neptune was discovered by applying the laws of gravity to Uranus' orbit and realizing that another, unseen mass was affecting said orbit. They looked where this unseen mass was, and whammo, they found Neptune. A similar calculation was made for Neptune's orbit, and Percival Lowell, acting on these calculations, spent many years and a considerable fortune to build an observatory just to find this missing planet. Lowell died before finding it. It turns out the calculations were wrong.

Nevertheless, using a different technique, Clive Tombaugh found Pluto at Lowell's observatory (which is still in use today).

It might be in an area frequented by cropdusters who fly very low over the ground.

Nah, who am I kidding, it's the poopoing planes.

I'm guessing it's a clamp for a mobile shoe shine operation.