They were soon able to gain the interior after the same manner in
which the pilot of the exploring expedition had accomplished it.
Monkey's sharp eyes had discovered a small opening that might be called
a slit in the solid wall, after the fashion of those to be seen in
the dwellings of Moors and Arabs and Turks. It was easy enough for
each boy in turn to squeeze himself through that slender gap, though
once there arose a serious doubt in Billy's mind as to whether he
would not stick fast, and have to be pushed through with a rammer,
much to his bodily discomfort.

Two fellows behind assisted his progress, while the others in advance
gave him a helping hand, so that finally Billy gained his end, though
he could long afterwards be seen ruefully rubbing his elbows and hips
as though they had been scraped in the passage.

After that they left their packs in one of the lower apartments, while
they roamed all through the wonderful interior. Apparently money
had not been spared in the erection of an imitation castle, though
Hugh found, in some places where what was supposed to be solid rock,
proved to be only wood, skillfully painted to resemble the more lasting
material.

"Whew! it has about forty rooms all told, I should say," observed
the steaming Billy after they had wearied of wandering about the strange
place, and came back to the apartment where their blankets and packs
had been deposited.

"Wonder how Aunt Susan will like the blooming old shack?" Alec was
heard to say as though some doubt had already commenced to enter his
mind.