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.