While we were examining the wreck we heard a distant “halloa” from the mainland.  There was Uncle Ed sitting on a pile of goods on the railroad bank looking for all the world like an Italian immigrant.  We answered with a shout and scrambled back to the clearing.  Then we ran splashing through the water, pushing the boat before us.  It didn’t take us long to load up and carry him back to the island.

A Rustic Table.

Uncle Ed entered into our fun at once.  He was as enthusiastic as a boy over the surroundings, and when we told him of the old bridge he started right off to investigate, taking the ax with him.  Soon he had pried off a number of the planks, which we used for a flooring to our tent.  Then he built us a table out of four forked sticks, driven into the ground, and supporting two cross sticks, on which a pair of planks were laid.

[Illustration:  Fig. 67.  The Rustic Table.]

The Small Filter.

“Well, now, boys,” said Uncle Ed, wiping the perspiration from his forehead, “I am as thirsty as a whale.  Where do you get your drinking water?  Is there a spring on the island?”

We told him that we used the river water.

“What, river water I That won’t do at all,” he cried.  “You’ll all have the typhoid fever.  We must build a filter.  I brought some charcoal with me for this very purpose.”

Taking one of our pails he broke a hole in the bottom of it and stuffed a sponge in the hole.  A layer of small stones was then placed in the pail, over this a layer of broken charcoal with the dust carefully blown out, then a layer of clean sand, and finally a layer of gravel.  Each layer was about two inches thick.  The pail was suspended from a branch in a cool place and proved an excellent filter, the water trickling out through the sponge being perfectly pure and sweet, no matter how dirty it had been when poured in; but the capacity of the filter was too small, and Uncle Ed said he would make us a larger one on the morrow if no spring was discovered in the meantime.

The sun was getting low in the west, and we therefore postponed the exploration of our island until the following day.  We had been up since four o’clock that morning and had done some pretty hard work; so, immediately after supper, we turned in and, lulled by the murmuring of the river, were soon fast asleep.

[Illustration:  Fig. 68.  The Small Filter.]

The Barrel Filter.

Immediately after breakfast the next day we started out in two parties to search the island.  The only discovery of any moment was that made by Dutchy’s party, which found a small island separated from ours by a narrow channel, through which the water ran like a mill-race.  No spring was discovered, so Uncle Ed had to construct his large filter.  Bill and I went over to Lumberville in search of a couple of cider barrels and a pailful of charcoal.  The barrels were placed one on top of the other after cutting