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called that of Nero, to the position where the obelisk now stands; its former site is stillmarked by a stone in the passage leading from sacristy to the choir of St. Peter’s. Afterthe obelisk had been moved along tins plane upon wooden rollers, the forty-six capstansplaced round the mound of earth were prepared for their work of raising: they were fixedin the ground on each side, and each had four arms or handspikes; the first and thirdarms were worked by a horse, and the other two each by from six to ten men : four of the
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Fig. 1537.
capstans acting upon as many blocks were used for drawing the foot of the obelisk for-ward, one block to each angle; the other capstans were employed to raise the obelisk intoa vertical position. The whole operation is amply described in a work compiled byFontana, and in which are engravings of the entire machinery.
The foundations prepared to receive this enormous weight were carefully executed: anexcavation 43 feet square, and to the depth of 24 feet, was made, and the bottom beingfound a clay, it was piled entirely over with oak and chestnut, with piles 18 feet in lengthand 9 inches in diameter, the bark being previously removed from them: upon these waslaid a bed of concrete, composed of basalt broken into small fragments, and mortar com-posed of lime and puzzolana. The total cost of the entire removal was about 9000/.
This obelisk, which now reposes on four pieces of metal, firmly run with lead into thepedestal, is one of those which Herodotus mentions as having been erected by Phero, sonof Sesostris, when he recovered from his blindness, and which were in height 100 cubits,and 8 wide. Pliny also mentions it: “ ejusdem remanet et alius centum cubitorum,quern post ca?citatem visu reddito ex oraculo Soli sacravit.”
Caligula transported it to Rome, and dedicated it to Augustus (Ammian. Marcell,lib. xvii.). When Constantine removed an obelisk from Egypt , after floating it on a raildown the Nile , and landing it at Alexandria, he put it on board another raft or shipprovided with 300 rowers: when it reached the Tiber, it was landed 3 miles from Rome ,and placed on rollers (cuniculis, or chamulcis impositum); then moved slowly to itsdestination through the Porta Ostiensis : lofty beams, and a forest of machines or capstanswere then made use of; the latter, worked by many thousand men, lifted it bodily, andplaced it erect upon its pedestal.
The various machines for raising weights mentioned by Vitruvius were made of timber,as were those called Scansoria, applied to the walls of a besieged town for the purpose ofsealing : these were so contrived that, like a scaffold, they could be quickly put together.The Tractoria were machines employed for raising those heavy masses with which the Romansconstructed their temples and public buildings ; the same author also mentions the Rota?,Rheda?, Cissite, Torni, &c., as in common use in his day; he also refers to the Charckesium,which is supposed to have been an upright timber, with another lying horizontally across thetop, and movable upon a hinge upward and downward, as well as having a horizontal motionaround, by which stones could not only be raised from the ground, but conveyed to theirintended situation. The tympanum, or hollow cylindrical wheel, are also alluded to byVitruvius , but he does not inform us how the men who turned it were disposed ; and weknow, too, that the ancients made use of powerful levers, wheels, and inclined planes for thepurpose of moving ponderous masses, or lifting heavy weights : but it cannot be deniedthat since Fontana constructed his machinery for raising the obelisks at Rome great im-provements have been made in this branch of mechanics; considerable attention has been
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