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HISTORY OF ENGINEERING.

Rook I.

Italy, celebrated for their acquirements in hydraulic architecture, met with employment andencouragement in Venice , and she must for centuries have been a school for the instructionof engineers.

Before we leave this portion of our subject, and proceed with an account of the worksexecuted since the destruction of the eastern and western empire, it is due to the engineersof Italy to acknowledge how much we are indebted to them for the science handed downthrough the middle ages, upon which our modern practice in the arts of construction isfounded.

The ancient writers are scanty in such observations as practical men seek after, and it isto be regretted that information upon many important and vast undertakings of the em-perors of Home is not more fully given.

Cities, harbours, roads, bridges, supplies of water, baths, drainage of vast districts, publicedifices of all denominations, were laid out and executed in a manner never yet surpassed,the majestic ruins of which are spread far and wide for our wonder and admiration. Thewhole circle of the building arts was employed in deep seas, in rapid rivers, and on mostdifficult sites, where foundations were raised to hear the extraordinary weights imposed uponthem. We must blush at the expensive but too often ill-dirccted efforts of the presentday, when we reflect on the well-proportioned and majestic structures which still remainin ami around the Imperial city. It must also be admitted, that we have not improved ontheir knowledge of construction ; and if Vitruvius , to whom wc have so often referred, hestudied by a mind bringing with it a spirit and judgment equal to the information found inthat author, it will be convinced that there is nothing new in the works of modern times.The builders of later generations too generally present to us only the lifeless form, whiletheir brethren of yore stamped on their erections all the glow and beauty of vitality.

About the middle of the fifteenth century, the arts were again encouraged. EeonBattista Alberti wrote his treatise, “ De Re TEdificatoria,” which, from its close resem-blance to the author alluded to, proves that Vitruvius was held in the highest consideration.When Alberti was employed by Pope Nicholas V. to repair the aqueducts at Rome ,particularly that of Aqua Virgine, he devoted himself to the study of Frontinus , andacquired a thorough knowledge of the principles which guided the ancient engineers.

Hydraulic architecture, after the splendid discoveries of Galileo and his successors,became more refined by the abstract and mathematical reasoning to which it was subjected ;but many of the calculations were formed upon erroneous and inefficient data, and con-sequently have become of little value, — a very common result when such calculations arenot accompanied by a practical acquaintance with the subject in question. Theory amipractice must go hand in hand ; the calculations of the one must he based on the experienceof the other, while the active energies of the practical man may be materially assisted bythe silent process of well-directed reflection. The authors of Italy , during the fifteenthand seventeenth centuries revived the writings of the classic period ; and in commentingupon the subjects they described, Palladio and other practical men were required to pro-vide illustrations : thus were the bridges of Caesar, Trajan , and the emperors brought underthe notice of the engineers of that period. The baths of the Romans also met with theirshare of enquiry, and little was left upon these subjects to the moderns in the way of in-terpretation ; they had only to apply their reasoning to what remained of the structures.

To the Romans we stand indebted for the knowledge that is interesting to us as amaritime nation. They first established in Britain ports and havens, marked out andformed roads from one end of our island to the other, which excite wonder even in thepresent day for the straightness of their course, and the solid manner in which many of themare executed. They established beacons on our coast, remains of which may be traced onsome of the heights which girt our isle ; within the circuit of the walls of Dover Castle,their pharos is still shown. It would be impossible to do justice to the people of thismighty nation : wherever they established themselves they introduced improvement, drainedmarshes, cleared lands, brought them into cultivation, and encouraged commerce.

Their stone cutting and artificers’ work of all kinds have served us for models; our verynomenclature upon the subject is derived from them. Of the solidity of their constructionswe have ample proof; and had they been left to the hand of Time alone, we might havederived many useful lessons from the study of those structures over whose ruins we nowlinger with wondering regret.