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HISTORY OF MARINE ARCHITECTURE.

of this object, it is only necessary to suppose that the power of the lever should beenlarged; it may be augmented and extended by the junction of another, orassisted by the addition of other powers. It was certainly for that reason thatArchimedes demanded nothing more than a place to stand upon, in order toraise or lift up the whole world. Those who are versed in the study of motiveforces, will not receive what this great man has said as mechanic gasconade :thev will sufficiently perceive its possibility; though with regard to the fixedpoint, as well as the materials of which a machine, that might raise and suspendthe earth, should be constructed, they may be unable to take him at his word,by furnishing what would be necessary for the purpose. It is, indeed, incon,-trovertibly true, that the mechanic powers may be multiplied to infinity ; but itis not less true, that the time required for setting them in motion closely ap-proaches infinity likewise. To lift up vessels completely manned and equipped,in short, to raise the greatest bodies, does not appear to an adept as the mostmarvellous consideration : it is not this circumstance that is astonishing; but itis certainly surprising and wonderful, that such heavy bodies should be raisedwith the alertness, celerity, and promptitude they were, or whirled into theair, and broken against the walls of the city by the most violent concussions.

“ It appears from the words of Plutarch, that the corvus of Archimedeswas considered as a species of crane, though certainly possessed of various powersexclusive of those given to it at present ; and, from the little resemblance whichit bore to it, ’twere perhaps, ridiculous to reckon it in the same class of machines.The author should have recollected, that the supporting point of the crane formsneither the lever, nor the balance, nor can the former be inclined in every direc-tion, as was the case with the corvus of Archimedes, that it turns round on thebeam which serves for its axis : had it indeed been otherwise, neither the axis,the drum in which the persons working the crane tread, nor the pullies them-selves, could have been applied to those purposes which were required in thecorvus. Polybius says positively, that the corvus of Archimedes was composedof a lever and balance; this appears the nearest to truth, and most capableof accounting for those effects of which he speaks, with a power of actionextraordinarily sudden and rapid. It was doubtless a beam or mast of greatlength, formed of several pieces, that is, of smaller masts joined together, forthe purpose of increasing its strength and steadiness. It was firmly fixed bystrong spurs, the whole being secured from space to space with hoops of ironinstead of ccrds, like the mast of a vessel composed of several spars, or pieces

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