his cooler judgment also warned him that the Ottoman power rested on a
perilous basis as long as Constantinople, the true capital of his
empire, remained in the hands of others. Mahomet could easily assemble a
sufficient number of troops for his enterprise, but it required all his
activity and power to collect the requisite supplies of provisions
and stores for the immense military and naval force he had ordered to
assemble, and to prepare the artillery and ammunition necessary to insure
success.

Early and late, in his court and in his cabinet, the young Sultan could
talk of nothing but the approaching siege. With the writing-reed and
a scroll of paper in his hand he was often seen tracing plans of the
fortifications of Constantinople, and marking out positions for his own
batteries. Every question relating to the extent and locality of the
various magazines to be constructed in order to maintain the troops was
discussed in his presence; he himself distributed the troops in their
respective divisions and regulated the order of their march; he issued
the orders relating to the equipment of the fleet, and discussed the
various methods proposed for breaching, mining, and scaling the walls.
His enthusiasm was the impulse of a hero, but the immense superiority of
his force would have secured him the victory with any ordinary degree of
perseverance.

The Ottomans were already familiar with the use of cannon. Amurath II had
employed them when he besieged Constantinople in 1422; but Mahomet now
resolved on forming a more powerful battering-train than had previously
existed. Neither the Greeks nor Turks possessed the art of casting large
guns. Both were obliged to employ foreigners. An experienced artilleryman
and founder named Urban, by birth a Wallachian, carried into execution
the Sultan's wishes. He had passed some time in the Greek service; but,