He had been thinking, during his last employment, upon the necessity which he had of some shelter.  A plan had suggested itself which he felt confident that he could carry into execution without any very great trouble.  The fog that now prevailed, and which was far different from the light mist of the previous day, accompanied also, as it was, by the damp south-west wind, made some sort of a shelter imperatively necessary, and that, too, before another night.  To pass this night in the fog would be bad enough; but if it should happen to rain also, his situation would be miserable indeed.

He now set out for the beach, and found, without much difficulty, some pieces of wood which were necessary to his purpose.  Bringing these back, he next looked about for a good situation.  There was a rock not far from the fire, and in front of this was a smooth spot, where the land was flat, and covered with short grass.  On the left it sloped to the brook.  This seemed to him to be the best place on the island.  It was sufficiently sheltered.  It was dry, and in case of rain the water would not be likely to flood it.  With all these it also possessed the advantage of being sufficiently conspicuous to any passing vessel which might be attracted by the signal-staff.  Here, then, Tom determined to erect his place of residence.

His first work was to select two long and slender pieces of wood, and sharpen the ends of them.  Then he drove each of them into the ground in such a way that their tops crossed one another.  These he bound fast together.  Two other stakes were driven into the ground, and secured in the same way, about six or seven feet off.  Another long piece of scantling was then placed so as to pass from one to the other of the two crossed sticks, so that it rested upon them.  This last was bound tight to the crossed sticks, and thus the whole structure formed a camp-shaped frame.

Over this Tom now threw the sail, and brought it down to the ground on either side, securing it there with pegs.  At the back of the camp a piece of the sail was folded over and secured so as to cover it in; while in front another piece of the sail hung down until it nearly reached the ground.  This could hang down at night, and be folded over the top by day.  Tom now tore up some sods, and laid them over the edge of the canvas on each side, where it touched the ground, and placed on these heavy stones, until at length it seemed sufficiently protected from the entrance of any rain that might flow down the roof.  His last task consisted in collecting a large quantity of moss and ferns from the woods, which he strewed over the ground inside, and heaped up at one end, so as to form a soft and fragrant bed.  When this was accomplished the camp was finished.