If you need to drill through wall, out the other side exactly in the right place — use…a compass.
Of course, in collaboration with the magnet, which should be put behind the wall just at the desired point: it will show the compass needle.
Recommend to read
FLYING ON THE SIDE
Model of a catamaran-class "P" with a sail-wing. Few people remember that the apparatus used for movements the aerodynamic forces, was created more than five thousand years ago. It was a...
STEAM – ENGINE
Even if the shoulder is already extensive experience in building boat-copies, still in the design of the new microtune he inevitably faces the problem of which engine to put in a...
