Experiments have been made to measure the sound-impulse produced in a telephone by ordinary speaking; but it is too feeble to excite even a delicate galvanometer. But a slight swing of the free end of the instrument affects the needle, which moves in a different direction according as the swing is south, north, west, or east. There is no doubt, as we observed in a recent paper on the subject, that in the behaviour of the telephone and the phenomena of its currents scientific men have a promising subject of inquiry. Meanwhile, as explained at the end of this article, the notion that it would at once supersede other forms of telegraphy or telephony will abate. A telephone has no advantage over a speaking-tube within the distances where a tube is available. Moreover the needlessly high price at which it is to be sold will be an effectual bar to its general use. To ask thirty-five pounds and twenty-five pounds for an article that could be sold at a profit for so many shillings, is not and ought not to be the way to commercial success. It is stated in a French scientific periodical that underground water may be discovered by observing the quivering of the air on a clear calm summer afternoon when the sun is low. If a well be dug at the spot where the quivering appears, a supply of water will, as is said, there be found. And as regards the influence of trees on moisture, careful observation has confirmed the theory that more rain falls on forests than on open plains; and comparing different kinds of trees it is found that the pine tribe get more water and retain more than leafy trees. Hence, it is said, pines are the best defence against sudden inundations, and the best means for giving freshness and humidity to a hot and dry climate such as that of Algeria, where attempts at amelioration have been made by planting, and by the digging of artesian wells.