spring at Alvarado, furnishes a corroborating instance of how this law of overflow operates. The spring was originally on the level of the shore until the sand drifted by degrees and formed a ridge twenty feet high, but the water appeared at the top of the ridge.
This law can be utilized in increasing the flow of water. As above mentioned, it was found that, by inclosing an overflowing spring tightly and allowing the inclosure to be terminated by a tube with an opening carried to a level below the fountain, the flow was increased because the channel was increased, and the resultant of the natural forces with it.
If an artificial connection be made with a stratum of water or water-bed, as by a tube tightly set in the earth or a series of tubes, and the suction-tube of a pump be attached thereto, we shall have the best conditions for a utilization of this newly discovered force in obtaining water for domestic purposes. The natural channels will thus be continued to the pump, and when this is operated (the air being lifted off) the new force acts as a handmaid in lifting the water. Many experiments fully prove this. As the water-deposits drawn upon are subterranean they are ample for all practical purposes; and, if these facts had been within the knowledge of Professor Buckland and the proposed company to which he has given such prominence, London could have been supplied with pure water without the least occasion for anxiety that the manufactories on the banks of the river Coln would be robbed of their portion.
The force, then, which we have demonstrated may be thus formulated: The resultant of the earth's centripetal and centrifugal forces acts impulsively upon the subterranean water-deposits, and tends to force them into and through the natural channels of the earth's crust.
| MARS AND HIS MOONS. |
By Professor JOHN LE CONTE,
OF THE UNIVERSITY OF CALIFORNIA.
THERE is no member of the solar system, with the exception of our moon, which can be studied under such favorable circumstances as the planet Mars; for, although Venus, when in inferior conjunction, is nearer to us than Mars in opposition, yet Venus, at this time, turns her darkened hemisphere toward the earth. Moreover, although Mars does not appear so large an object in the telescope as Jupiter, yet he is in reality seen on a much larger scale, not only on account of his much greater proximity to us, but because, being likewise much nearer the sun, his surface is much more brilliantly illuminated, so that a much higher telescopic power can be advantageously
