In the collection of "Notes" on Mild Steel and Constructional Steelwork, which form the contents of the present volume, no attempt has been made to treat the subject from the point of view of Applied Mechanics as ordinarily understood, nor are the theories of construction, nor the calculations for buildings or engineering structures referred to, except so far as may be required incidentally in connection with the subject-matter discussed, while the great range of the subjects upon which the Notes treat, and the severe limitations which are necessarily imposed, must form the only excuse which the writer has to offer for the obvious insufficiency of treatment of the items dealt with.

It has been assumed that the junior draughtsman of the architectural or engineering professions has been, at least to some extent, properly grounded in the theory of construction, and that he has acquired an elementary knowledge of the determination of stresses in the structures with which he has to deal.

It has, however, come within the experience of the writer that between the carefully calculated stress-sheet or correctly drawn graphic diagram, and the completion of a working drawing which shall successfully pass the ordeal of criticism in the girdermaker or bridge- or roof-builder's yard, there is sometimes found a gap, not always successfully bridged, and it becomes occasionally evident that the ability to produce, let us say, a correct graphic analysis of the stresses on a roof principal and the ability to design a sound riveted connection are not quite one and the same thing.

It is true that excellence and soundness of design are not to be acquired from books alone, and that close study, observation, and experience must go hand-in-hand to arrive at that result. It is, however, the hope of the writer that the Notes now offered will assist the student, at all events, in the study and observation of such good examples of Steel Construction as may come within his reach, and in the practical application of a material which has taken, and is likely to maintain, so important a position in both Architectural and Engineering Construction.

The education of the designer of Constructional Steelwork is not, however, completed even when to a sound knowledge of theory he has added to that knowledge the experience of the practical aspects of design. He will, if he be wise, endeavour, so far as opportunity may be given him, to trace back the previous history of the material he has been dealing with; he will place himself, mentally and (as far as is possible to him) by personal observation, in touch with the centres of the Steel-making Industry, the Blast Furnace, the Cinder Heap, the "Sow" and her "Pigs," the dazzling radiance of the molten metal in the open hearth or the converter, the methods (to say nothing of the risks and anxieties) of the Steel Founder, the ruddy atmosphere of the Annealing Furnace, and the spectral shapes of castings, refracted by the waving and glowing gases as they undergo the ordeal which relieves internal stress and makes them ductile and tough, the Ingot, the Soaking Pit, the clangour, and hiss and roar of the Rolling Mills.

The scene changes, and he will follow the completed sections and shapes to the Plater's yard, the Templet-maker's, Machine and Smith's shops, the Pickling or Galvanizing Tanks, and watch the processes whereby Drilling Machine, Punching Machine, Riveting Machine, Pneumatic Hammer with its incessant rattle, Cold Saw with its halo of sparks, Hydraulic Press, and the like, shape and fashion his material into the form he has evolved on paper; and perhaps he then becomes conscious, as the offspring of his thought grows into visible bodily shape before his eyes, that there are certain details in his design which he will take care to improve on a future occasion.

Again the scene changes, the riveted sections of steelwork, the castings, the cases of bolts and nuts, the bags of rivets, have all left the contractor's yard, some by rail, some perchance by sea, and then the multitudinous practical requirements which surround the Erection of Constructional Steelwork become evident, whether the Structure be some Bridge of great span over a ravine or rapid river, a Skeleton Steel "Skyscraper" many stories high, a large Caisson or Lock Gate for a Dock Entrance, or whether it be the simpler and humbler forms of Builders' Ironwork, and the erection of a few simple columns, girders, or roof principals.

All these things, and many more, noted with the observant eye, and the receptive and willing mind, will form so many rungs in the ladder whereby the junior draughtsman, be he Architect or Engineer, may climb, as regards this branch of his profession, to efficiency, success, and the honourable reward of his industry.

The application of Steel to that mode of construction known as "Ferro-Concrete," "Armoured Concrete," or "Concrete Steel" demands separate treatment, and is not alluded to in this volume. This subject, together with that of the protection of Constructional Steelwork from the effects of fire, the present writer must leave until such period as time and opportunity may indicate.

London,

November, 1906.

H. F.