Weighing scale
The balance (also balance scale, beam balance and laboratory balance) was the first mass measuring instrument invented. In its traditional form, it consists of a pivoted horizontal lever with arms of equal lengththe beamand a weighing pan suspended from each arm (hence the plural name ""scales" for a weighing instrument). The unknown mass is placed in one pan and standard masses are added to the other pan until the beam is as close to equilibrium as possible. In precision balances, a more accurate determination of the mass is given by the position of a sliding mass moved along a graduated scale. Technically, a balance compares weight rather than mass, but, in a given gravitational field (such as Earth's gravity), the weight of an object is proportional to its mass, so the standard masses used with balances are usually labeled in units of mass (e.g. g or kg).
Digital painting
The earliest graphical manipulation program was called Sketchpad. Created in 1963 by Ivan Sutherland, a grad student at MIT, Sketchpad allowed the user to manipulate objects on a CRT (cathode ray tube). Sketchpad eventually led to the creation of the Rand Tablet for work on the GRAIL project in 1968, and the very first tablet was created. Other early tablets, or digitizers, like the ID (intelligent digitizer) and the BitPad were commercially successful and used in CAD (Computer Aided Design) programs. Modern day tablets are the tools of choice by digital painters. WACOM is the industry leader in tablets which can range in size from 4” x 6” all the way to 12” x 19” and are less than an inch thick. Other brands of graphic tablets are Aiptek, Monoprice, Hanvon, Genius, Adesso, Trust, Manhattan, Vistablet, DigiPro, etc.
All these graphic tablets have the basic functions of a mouse, so they can be used as a mouse, not only in graphic editors but also as a replacement for a mouse, and they are compatible with practically all Windows and Macintosh software.