A closely-fitting adjustable piston is provided at one end.
AB is the axis of rotation, BC an adjustable FIG.
Finally, I invented a new Adjustable Post-hole, which I thought would make my fortune.
II, S is kept permanently closed, and corresponding values of H and B are determined by one of the two methods already described, the strength of the battery-current being varied by means of the adjustable resistance R.
The magnet between the poles of which the rectangular signal coil moves is built up of a number of thin flat horseshoe-shaped permanent magnets of a special quality of steel, and is provided with adjustable pole pieces.