How to Make a Simple Water Filter – The Small Filter – excerpt from the book “The Scientific American Boy” by A. Russell Bond
“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 river water.
“What, river water!
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.
The SCIENTIFIC AMERICAN BOY OR The Camp at Willow Clump Island
By A. RUSSELL BOND
MUNN & CO., Publishers