THIS book is one of a series of manuals now being published by Messrs. Cassell and Co., intended for the use of technical students, and claims, to quote the preface, “to put before non-mathematical ...

WHAT is the force of the word “rigid,” introduced into the statement and proof of the parallelogram of forces and other theorems in Statics, as quoted by Mr. W. E. Johnson from the ordinary text-books ...