_Emily._ And are not fountains, of the nature of springs?
_Mrs. B._ Exactly. A fountain is conducted perpendicularly upwards, by the spout or adjutage A, through which it flows; and it will rise nearly as high as the reservoir B, from whence it proceeds. (Plate 14. fig. 2.)
_Mrs. B._ Because it meets with resistance from the air, in its ascent; and its motion is impeded by friction against the spout, where it rushes out.
_Emily._ But if the tube through which the water rises be smooth, can there be any friction? especially with a fluid, whose particles yield to the slightest impression.
_Mrs. B._ Friction, (as we observed in a former lesson,) may be diminished by polishing, but can never be entirely destroyed; and though fluids, are less susceptible of friction, than solid bodies, they are still affected by it. Another reason why a fountain will not rise so high as its reservoir, is, that as all the water which spouts up, has to descend again, it in doing so, presses, or strikes against the under parts, and forces them sideways, spreading the column into a head, and rendering it both wider, and shorter, than it otherwise would be.
At our next meeting, we shall examine the mechanical properties of the air, which being an elastic fluid, differs in many respects, from liquids.
1. (Pg. 129) Why do not the frequent rains, fill the earth with water?
2. (Pg. 129) Why will vapour rise? to what height will it ascend, and what will it form?
3. (Pg. 129) How may drops of rain be formed?
4. (Pg. 130) What becomes of the water after it has fallen to the earth?
5. (Pg. 130) What is the difference between rain water, and that from springs?
6. (Pg. 130) Why is rain more pure than spring water?
7. (Pg. 130) Why is spring water more agreeable to the palate?
8. (Pg. 131) What causes the water to collect and form springs?
9. (Pg. 131) Why cannot water penetrate through clay?
10. (Pg. 131) What is represented by fig. 9, plate 13?
11. (Pg. 132) How can you account for its rising upwards, as represented at C?
12. (Pg. 132) In conveying water by means of pipes, how must the reservoir be situated?
13. (Pg. 132) What is the instrument called, which is represented in plate 14, fig. 1,--and how does it operate?