principles, and the student will find in this system a valuable aid in determining the stresses on all irregularlyframed structures. Although the work has been designed mainly for the class of readers above referred to, it is further hoped that it may prove a useful book of Reference to those engaged in the profession generally. Several chapters are devoted to the practical side of the subject-those relating to the Strength of Joints, and to Punching, Drilling, Rivetting, and other processes connected with the manufacture of Bridges, Roofs, and Structural work generally, being the result of many years' experience in the bridge-yard; and it is hoped that the information given on this branch of the subject may be of value to the practical bridge-builder. PRESTWICH, January, 1891. S. A. Area and Elongation of Process Paint a Pre- servation against Mois- 42. Shearing Strength Wrought Iron-Table of Crushing Strengths, |