GRAPHICAL and mechanical representations of practical equations are especially useful to the engineer, and this volume has been written to provide a systematic course in the subject. The first four chapters are devoted to stationary adjacent and sliding scales; network or intersection and alignment charts for equations in three variables and combinations of all these methods of solution. In the final chapter, the fitting of equations to experimental data is discussed. The treatment is quite elementary and involves only a working knowledge of logarithms, algebra and plane geometry, while a little calculus is required in the section on empirical equations. With the volume is provided a very clear reproduction of the logarithmic scales prepared by the late Prof. Lipka.
By Prof. Charles O. Mackey. Pp. vii + 130. (New York: John Wiley and Sons, Inc.; London: Chapman and Hall, Ltd., 1936.) 12s. 6d. net.