raising in the centre of the square of St. Peter's the only obelisk which remained standing, but partly interred, near the wall of the Sacristy, where was formerly the Circus of Nero. Other pontiffs had had the same wish, but the difficulty of the enterprise had prevented the execution.

   "This obelisk, or pyramid, is of red granite, called by the ancient Romans, Marmor Thebanum (Theban marble), on account of having been worked near Thebes, in Egypt, whence it was transported to Rome in the time of Cæsar. Of the immense number in Rome, this is the only one remaining entire; it is without hieroglyphics, 84 feet high, 8 feet 6 inches wide at the base, and 5 feet 6 inches at the

   top. One cubic foot of this granite weighs about 160 pounds; so that the whole weight of the obelisk must be somewhat less than 759,000 lbs. Of the manner in which the Egyptians and Romans moved these enormous masses we have no idea, and so many centuries having elapsed since such a thing had been done, this proposition of Sixtus V. was considered so novel, that a general assembly was called of all the mathematicians, engineers, and learned men from various parts of Europe; and, in a congress held by the pope, more than 500 persons presented themselves, bringing with them their inventions; some with drawings, some with models, others with writings or arguments.

   "The greater number were for removing it by means of an iron carriage and thirty-two levers. Others invented a half wheel, on which the obelisk was to be raised by degrees. Some proposed screws, and others thought of carrying it upon slings.

   "Bartolomeo Ammanati, a Florentine architect and sculptor, sent expressly by the grand duke, presented himself before the pope, without either models or designs, and requested a year to consider it; for this he was most severely reprimanded by the pontiff. Fontana exhibited his wooden model, with a leaden pyramid, which, by means of a windlass and crane, was raised and lowered with the greatest facility; he explained the nature of these machines and movements, and gave a practical proof

   of their capability by raising a small pyramid in the mausoleum of Augustus, which was in a ruinous condition. After many disputes, Fontana's invention was approved; but, as he had not yet acquired a name of sufficient importance, the execution of it was committed to two architects of renown, Giacomo della Porta and Bartolomeo Ammanati.—These immediately commenced a scaffold in the centre of the square where the obelisk was to stand.

 Prev. P 19/268 next