200 blocks weighing 12 cwt. apiece.[7] Stella relates
that the Genoese armament sent against Cyprus, in 1373, among other great
machines had one called _Troja_ (_Truia_?), which cast stones of 12 to 18
hundredweights; and when the Venetians were besieging the revolted city of
Zara in 1346, their Engineer, Master Francesco delle Barche, shot into the
city stones of 3000 lbs. weight.[8] In this case the unlucky engineer was
"hoist with his own petard," for while he stood adjusting one of his
engines, it went off, and shot him into the town.

With reference to such cases the Emperor calculates that a stone of 3000
lbs. weight might be shot 77 yards with a counterpoise of 36,000 lbs.
weight, and a shaft 65 feet long. The counterpoise, composed of stone shot
of 55 lbs. each, might be contained in a cubical case of about 5-1/2 feet
to the side. The machine would be preposterous, but there is nothing
impossible about it. Indeed in the Album of Villard de Honnecourt, an
architect of the 13th century, which was published at Paris in 1858, in
the notes accompanying a plan of a trebuchet (from which Professor Willis
restored the machine as it is shown in our fig. 19), the artist remarks:
"It is a great job to heave down the beam, for the counterpoise is very
heavy. For it consists of a chest full of earth which is 2 great toises in
length, 8 feet in breadth, and 12 feet in depth"! (p. 203).

Such calculations enable us to understand the enormous quantities of
material said to have been used in some of the larger mediaeval machines.
Thus Abulfeda speaks of one used at the final capture of Acre, which was
entrusted to the troops of Hamath, and which formed a load for 100 carts,
of which one was in charge of the historian himself. The romance of
Richard Coeur de Lion tells how in the King's Fleet an entire ship was
taken up by one such machine with its gear:--

"Another schyp was laden yet
With an engyne hyghte Robinet,
(It was Richardys o mangonel)
And all the takyl that thereto fel."

Twenty-four machines, captured from the Saracens by St. Lewis in his first
partial success on the Nile, afforded material for stockading his whole
camp. A great machine which cumbered the Tower of St. Paul at Orleans, and
was dismantled previous to the celebrated defence against the English,
furnished 26 cart-loads of timber. (_Abulf. Ann. Muslem_, V. 95-97;
_Weber_, II. 56; _Michel's Joinville_, App. p. 278; _Jollois, H. du Siege
d Orlea