"At the suggestion of the publishers, this work was undertaken to form one of their series of Dictionaries and Cyclopeadias. In this view, it has been the intention to make it a complete course of instruction and book of reference to the mechanic, architect and engineer. It has not, therefore, been confined to the explanation and illustration of the methods of projection, and the delineation of objects which might serve as copies to the draughtsman, matters of essential importance for the correct and intelligible representation of every form; but it contains the means of determining the amount and direction of strains to which different parts of a machine or structure may be subjected, and the rules for disposing and proportioning of the material employed, to the safe and permanent resistance of those strains, with practical applications of the same."