THE microseismograph, devised a few years ago by Prof. Vicentini, of Padua, is now well known as one of the most valuable of the vertical pendulums used in Italy for recording earthquake movements.

Horizontal lines run left to right, parallel to the horizon, with slope 0 and equation y = k. Vertical lines run top to bottom, perpendicular to the horizon, with undefined slope and equation x = k.

Historically, resolution is understood to mean “limiting resolution,” or the point at which adjacent elements of an image cease to be distinguished. Various disciplines measure and specify resolution ...