Author: Brett, C W
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Brett, C W
The Minister of Transport has caused a circular to be issued to all highway authorities in Great Britain drawing attention to the provision of the Bridges Act, 1929. The main provisions of this Act are designed to facilitate the procedure for the reconstruction of weak bridges in private ownership, e.g., in the ownership of railway companies, canal companies, etc. Many of these bridges, as is well known, are not fitted to carry modern traffic, and the restrictions which their owners are authorised by law to impose on their use by heavy vehicles have caused considerable inconvenience and loss to trade and industry.
In the Middle Ages, when mankind had considerably more leisure than at present for the consideration of what are now termed academic questions, one of the favourite subjects of discussion is said to have been, "Which came first; the hen or the egg?" No satisfactory conclusion appears ever to have been reached, and a busy world has since decided that the solution of the problem is one of the things that do not matter. We might ask nowadays, and with profit-the question being by no means as academical as it seems -who came first; the architect, or the engineer, civil, mechanical or structural? The first enterprising arboreal who bent a branch to serve as a foundation, or as a shelter for its tentative home; the first prehistoric man who adapted a cave to the purposes of a dwelling, was only imitating what the lower animals had done before: employing materials of the nature and properties of which instinct first, and a process of trial and error later, had afforded some rough empirical knowledge. He was thus certainly a structural engineer, one, that is, who employs materials for the purpose, first and foremost, of making a structure, even as the beaver, or the bird had done before him. Of purposive architectural design, or of knowledge of civil or mechanical engineering in all this there is little trace; the materials at hand were taken and adapted, according to their nature and suitability to a crude purpose. It seems almost indisputable, therefore, that a knowledge of the properties of materials, combined with eventual experience of their behaviour when built into a structure, must have been the primitive, and almost simultaneous bases of all knowledge of structures. These, and the selection of a suitable site and foundation; a tree, or a rock; a hummock, the open plain, or a treacherous and marshy tract necessitating, at the dictate of experience, the use of piles mask the early stages in the evolution of the structural engineer. His subsequent progress and development have been due to his increasing knowledge of materials and of their applications, but, more especially, of their limitations. To those with which nature originally endowed him he has added others. He has laid under contribution the discoveries of chemistry, and metallurgy, and has himself invented, and inspired the invention of the new materials suited to the new requirements he is called upon constantly to fulfil.
The introduction of scientific engineering methods in the measurements of racing yachts is probably a matter in which few of our readers have ever had the opportunity of indulging. First of all, to those who know little of sailing, and still less of the complications of measurement for "rating" of sailing yachts, we should state that before a boat can compete in any but handicap races she must be measured in order to see that she complies strictly with the rules laid down for "class" yachts.