Horticulturists have in some places conducted this heated water by underground pipes through their gardens, and thus produced a semi-tropical vegetation.
Human contrivances for lifting water to higher elevations are various. Archimedes invented a screw for this purpose. The siphon, the chain pump, the ordinary lifting pump, the force pump, and some other inventions are applied to do this work. It would be a profitable exercise to study out the philosophy of these water lifters. You can also make them for yourself. The illustration of the forms of siphons and their various uses, for example, as given in this article, will well repay careful study.
SHOWING THAT PRESSURE DEPENDS UPON DEPTH.
Another way in which water acts as a friend to man, is in its hygienic effects. Think of the numberless uses of ice in summer, and how grateful to the fevered lips is ice! The invalid seeks in summer the cool sea breeze, freighted with its finely divided and stimulating salts and mineral vapors. In winter the genial atmosphere of Florida or the Gulf will fan the patient’s faded cheek. Or perhaps some health resort may be sought where there are mingled with the waters valuable medicinal restoratives. Vermont has the greatest number of these, but they are found at Sharon, Avon, Clifton, and Saratoga; while the hot springs of Arkansas have a great reputation, and who knows but what in some of the wonderful bath fountains of the West we may yet find what Ponce de Leon sought, the elixir which should transform old age into blooming youth. The latest new idea in medical practice is the hot water cure, which consists in drinking an indefinite amount of hot water whenever opportunity makes it possible. Public fountains are good temperance lectures.
SHOWING THE PRINCIPLE OF ARTESIAN WELLS.
One must travel in oriental lands, however, to learn all the sweet and beautiful significance of that one word, Water, which is so often used in the Bible as the best symbol of God’s abounding mercy.
Note.—The cuts in this article are from “Elements of Physics,” by Prof. A. P. Gage, the richest contribution to experimental philosophy printed in many years. Teachers as well as students will find it full of valuable suggestions.