A considerable time having elapsed since the publication of the 2nd Edition of this work, which was the last that had been revised by the Author, his death occurring soon after, a new Edition that would embrace recent improvements and examples was much required. Our stock of knowledge regarding the strength of materials has been largely increased, owing to the labours of Hodgkinson, Kirkaldy, and others. The rapid development of the railway system throughout the world has contributed greatly to the introduction of new methods and to the multiplication of examples in the art of construction. More perfect and scientific appliances in the erection of large works have been substituted for the primitive methods used in the last generation. These have all tended more or less to tax the ability and knowledge of the carpenter. The opening up and development of the resources of new countries have introduced varieties of timber, many of them possessing useful properties, not the least of which is that of resisting the attack of sea worms and insects - a cause of destruction that has hitherto been a source of much anxiety to the Profession.

In order to adapt this work as far as possible to the requirements of the modern carpenter, it has been necessary to re-write the articles on Pillars, Bridges, and Timber; to add new sections on Coffer-dams, Scaffolds, etc.; and to revise the remainder of the work throughout. And for the more complete illustration of these subjects several new Plates and Woodcuts have been added.

The Editor trusts that this Edition will merit the confidence of the Profession as a book of reference, and afford at the same time valuable assistance to the student.

London, 20th April, 1871.