Abridgment of vector calculating devices

In the analysis or solution of a-c. problems, it is frequently necessary to convert vector quantities from the exponential or polar form into complex numbers, or vice versa. This paper describes: a. A device by means of which such conversions may be performed mechanically. b. A device by means of which vector quantities expressed exponentially may be added or subtracted without prior conversion into the complex numbers. c. A slide rule with trigonometric and hyperbolic scales so disposed that conversions of vector quantities from one mathematical form into another, or the evaluation of trigonometric or hyperbolic functions of complex variables may be obtained with ordinary slide rule ease and rapidity.