Transient performance of electric elevators

Bassett Jonesl It strikes me that the paper by Messrs. Lindquist and Kearsley presents a method of solving a very large class of differential equations of almost any order and complexity involving both continuous and discontinuous functions. The method should prove of inestimable value in mathematical engineering. As the authors have shown, the method makes the solution of even an unknown equation, relating two or more variables, a practical possibility provided only that the actual physical relationship between these variables can be observed and graphically represented. It is not required that the mathematical expression for this relation be known, or if known in abstract form, it does not follow that the detail form of the expression is req uired.