The following curious account of the removal of the obelisk in the Circus Vaticanus to the centre of St. Peter's square, by Domenico Fontana, is extracted from Milizia's life of that famous architect. It shows plainly that the Egyptians must have attained great skill and perfection in mechanics and engineering, to have been able to quarry out obelisks at least a third larger, and convey them often several hundred miles, to the places where they erected them.

"Sixtus V. was now desirous of 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.

"Fontana being justly displeased that his own discovery should not be entrusted to his execution, went to the pope, and respectfully represented to him, that no one could so properly execute a design as the inventor. Sixtus was persuaded, and committed the entire direction of it to him. The architect then commenced his work with the utmost celerity. He dug a square hole of 44 feet, in the piazza, 24 feet deep, and finding the soil watery and chalky, he made it firm by strong and massive piles. At the same time he had ropes made, three inches in diameter, 1500 feet long, an immense quantity of cords, large iron rods to strengthen the obelisk, and other pieces of iron for the cases of the cranes, pins, circles, pivots, and instruments of every kind. The iron to secure the obelisk alone amounted to 40,000 lbs., and was made in the manufactories of Rome, Ronciglione, and Subbiaco. The beams, taken from the woods of Nettuno, were of such a prodigious size, that each was drawn by seven pair of buffalos. From Terracina, elm was brought, for the caseing, and Holm oak for the shafts of windlass; and to prevent the ground from giving way, it being soft and marshy, in consequence of the great weight, he made a bed with two layers of timber, crossing each other in a contrary direction. On this foundation he placed the castle or carriage, which had eight columns: each of these columns was composed of so many thick planks, that they measured 13 feet in circumference. These were united together by thick cords, without screws, in order to be done and undone with greater quickness. The height of the beams was required to be 90 feet; and not any being of that length, they were placed one on the other, and united by iron bands. These columns were strengthened by forty-eight braces, and tied together on all sides. The obelisk was entirely covered with double mats, to prevent its being injured; it was then surrounded by planks, over which were placed large rods of iron, and these embracing the thick part underneath, came directly over the four faces of the mass, which thus became totally encircled with these coverings. The whole pyramid thus weighed one million and a half pounds. Fontana calculated that every windlass, with good ropes and cranes, would be able to move 20,000 lbs. weight; and consequently forty would move 800,000, and he gained the rest by five levers of thick beams 52 feet long.