4

PREFACE.

by die miner, and transported by the engineer to the smelting station, arethere skilfully blended by the iron-master (manufacturer), who treats themin a furnace appropriately constructed, along with their due proportions ol'(lux and fuel, whereby he reduces them to cast iron of certain quality,which he nins off at the right periods into rough pigs or regular moulds ;he then transforms this crude metal, by mechanical and chemical agencies,into bar and plate iron of various sizes and shapes, fit for the general market ;he finally converts the best of the bars into steel, by the cementation fur-nace, the forge, and the tilt-hammer ; or the best of the plates into tin-plate.When farther worked by definite ant^nearly uniform processes into objectsof very general demand in all civilized countries, these iron and steel barsstill belong to the domain of manufactures ; as, for example, when madeinto anchors, chain-cables, files, nails, needles, wire, &c.; but when theiron is fashioned, into ever varying and capricious forms, they belong eitherto the general business of the founder and cutler, or to the particular call-ing of some handicraft, as the iocksmith, gratesmilh, coachsmith, gunsmith,tinman, &c.

Such are the principles which have served to guide me in selecting arti-cles for the present volume. By them, as a clew, I have endeavored tohold a steady course through the vast and otherwise perplexing labyrinthof arts, manufactures, and mines ; avoiding alike engineering and mechan-ical arts, which cause no change in the texture or constitution of matter,—and handicraft operations, which are multiform, capricious, and hardly sus-ceptible of scientific investigation. In fact, had such topics been introducedinto the volume, it would have presented a miscellaneous farrago of incon-gruous articles, too numerous to allow of their being expounded in a man-ner either interesting or instructive to the manufacturer and the metallurgist.I readily acknowledge, however, that T have not been able to adhere alwaysso rigorously as I could have wished to the above rule of selection ; havingbeen constrained by intelligent and influential friends to introduce a fewarticles which I would gladly have left to the mechanical engineer. Ofthese Printing is one, which, having had no provision made for it in myoriginal plan, was too hastily compiled to admit of my describing, withsuitable figures, the flat-printing automatic machine of Mr. Spottiswoode,wherewith the pages of this volume were worked off; a mechanism whichI regard as the most elegant, precise, and productive, hitherto employed ioexecute the best style of letter press.

I have imbodied in this work the results of my long experience as aProfessor of Practical Science. Since the year 1805, when I entered atan early age upon the arduous task of conducting the schools of chemistryand manufactures in the Andersonian Institution, up to the present day,I have been assiduously engaged in the study and improvement of most ofthe chemical and many of the mechanical arts. Consulted professionallyby proprietors of factories, workshops, and mines of various descriptions,both in this coufitry and abroad, concerning derangements in their opera-tions, or defects in their products, I have enjoyed peculiar opportunities ofbecoming familiar with their minutest details, and have frequently had thegood fortune to rectify what was amiss, or to supply what was wanting.Of the stores of information thus acquired, I have availed myself on thepresent occasion; careful, meanwhile, to neglect no means of knowledgewhich my extensive intercourse with foreign nations affords.

1 therefore humbly hope that this work will prove a valuable contributionto the literature of science, serving —

In the first place, to instruct the Manufacturer, Metallurgist, and Trades-man, in the print iples of their respective processes, so as to render them in