HISTORY OF MARINE ARCHITECTURE.

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fall, and by that contrivance, conducting as a pilot the beak of the vessel, aswell as at the same time grappling its prow, he depressed the opposite end of themachine within the walls. When he had raised the head nearly perpendicular,he held the arm of the machine motionless ; but presently loosening the chainby means of a roller, or pulley, in some instances the vessels fell on theirbroadsides, in others on their quarter deck; but the greater part being preci-pitated from an height upon their sterns, were submerged and filled with water.

“ If these furious corvi had bnly made their appearance in the first instanceat the siege of Syracuse, and if it were not known that the Greeks had beenprovided with them long before the time of Archimedes, as has been alreadyshown, some doubts might arise concerning the prodigious effects attributed tothem ; but the facts are too well attested, and too frequently repeated by theGreek as well as Latin historians, to permit of disbelief. They are deserving ofcredit not only because the matter is possible, but is mentioned again, withoutinterruption, by contemporary writers, and their immediate successors ; it is alsofarther observable, that they speak of the corvus as an existing machine, wellknown and very common in the defence of places: for this is constantly thecase with regard to the lesser corvi at least, and particularly those which wereused to seize or lift up individual soldiers, and carry them over the walls ofthe besieged citv.

“ What renders the account of Plutarch, far as it regards the wars of theRomans, more entitled to respect, is the fact, that he wrote in Rome itself whathe relates of its history, that he moreover did this on the authority not merelyof their authors, but of the officers and generals who had been witnesses ofthe events of which he spoke, and who had actually been at the siege ofSyracuse.

“ As nothing is to be found in Polybius that can assist the reader in dis-covering the construction and acting principle of the corvus , and as whatever issaid upon the subject constantly refers to its effects alone, little positive informa-tion can be expected from him ; but, notwithstanding the silence of this greatauthor, the secret is not, perhaps, impenetrable. With the assistance of somedegree of inventive capacity, a portion of research, a tolerable knowlege ofmechanics, and certain expressions which have fallen from historians, and otherwriters, it is possible to discover, if not the true corvus of Archimedes, one ofsufficient power to produce great effects, without losing sight of that simplicityfor which the beautiful contrivances of antiquity are remarkable. In pursuit

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