s
soft, and the keen dagger at once notched off a small piece of the
burred end. Again and again he tried, and each time a small piece of
metal flew off. After each cut he examined the edge of the dagger, but
it was well tempered, and seemed entirely unaffected.

He now felt certain that, with patience, he should be able to cut off
the projecting edges of the rivets, and so be able to free his hands.
He, therefore, now examined the fastenings at the ankles. These were
more heavy, and on trying them, the iron of the rivet appeared to be
much harder than that which kept the manacles together. It was,
however, now too dark to see what he was doing, and concealing the
dagger again, he lay down with a lighter heart than he had from the
moment of his capture.

Even if he found that the lower fastenings of the chain defied all his
efforts, he could cut the rivets at the wrists, and so free one end of
each chain. He could then tie the chains round his legs, and their
weight would not be sufficient to prevent his walking.

Chapter 13: The Pirates' Raid.

As soon as it was daylight next morning, Francis was up and at work.
His experiments of the evening before were at once confirmed. Three or
four hours' work would enable him to free his wrists, but he could make
no impression on the rivets at his ankles. After a few trials he gave
this up as hopeless, for he was afraid, if he continued, he would blunt
the edge of the dagger.

For an hour he sat still, thinking, and at last an idea occurred to
him. Iron could be ground by rubbing it upon stone, and if he could not
cut off the burr of the rivet with the dagger, he might perhaps be able
to wear it down, by rubbing it with a stone.

He at once turned to the walls of his cell. These were not built of the
unbaked clay so largely used for houses of the poorer class in Northern
Egypt, but had evidently been constructed either as a prison, or more
probably as a strong room where some merchant kept valuable goods. It
was therefore constructed of blocks of hard stone.

It seemed to Francis that this was sandstone, and to test its quality,
he sat down in the corner where the guard had, the night before, placed
his supply of food and water. First he moistened a portion of the wall,
then he took up a link of his chain, and rubbed for some time against
it. At last, to his satisfaction, a bright patch showed that the stone
was capable of wearing away iron. But in vain did he try t