Soon after this, however, Frank persuaded him to try it again, and this time they went on horseback.  Both the Elmer horses were accustomed to the sound of fire-arms, and warranted, when purchased, to stand perfectly still, even though a gun should be rested between their ears and discharged.

This time, having gone into a more open country, the hunters were successful; and having shot his first deer, and being well smeared with its blood by Frank, Mark came home delighted with his success and anxious to go on another hunt as soon as possible.

The country to the east of Wakulla being very thinly settled, abounded with game of all descriptions, and especially deer.  In it were vast tracts of open timber lands that were quite free from underbrush, and admirably fitted for hunting.  This country was, however, much broken, and contained many dangerous “sink holes.”

In speaking of this section, and in describing these “sink holes” to the Elmers one evening, Mr. March had said,

“Sinks, or sink holes, such as the country to the east of this abounds in, are common to all limestone formations.  They are sudden and sometimes very deep depressions or breaks in the surface of the ground, caused by the wearing away of the limestone beneath it by underground currents of water or rivers.  In most of these holes standing water of great depth is found, and sometimes swiftly running water.  I know several men who have on their places what they call ‘natural wells,’ or small, deep holes in the ground, at the bottom of which flow streams of water.  Many of these sinks are very dangerous, as they open so abruptly that a person might walk into one of them on a dark night before he was aware of its presence.  Several people who have mysteriously disappeared in this country are supposed to have lost their lives in that way.”

This conversation made a deep impression upon Mark, and when the boys started on horseback, one dark night towards the end of March, with the intention of going on a fire hunt in this very “sink hole” country, he said to Frank, as they rode along,

“How about those holes in the ground that your father told us about the other night.  Isn’t it dangerous for us to go among them?”

“Not a bit of danger,” answered Frank, “as long as you’re on horseback.  A horse’ll always steer clear of ’em.”

When they reached the hunting-ground, and had lighted the pine-knots in their fire-pans, Frank said,

“There’s no use our keeping together; we’ll never get anything if we do.  I’ll follow that star over this way”—­and he pointed as he spoke to a bright one in the north-east—­“and you go towards that one”—­pointing to one a little south of east.  “We’ll ride for an hour, and then if we haven’t had any luck we’ll make the best of our way home.  Remember that to get home you must keep the North-star exactly on your right hand, and by going due west you’ll be sure to strike the road that runs up and down the river.  If either of us fires, the other is to go to him at once, firing signal guns as he goes, and these the other must answer so as to show where he is.”