Scientific

Waikato Times, Volume XXVIII, Issue 2274, 5 February 1887, Page 2 (Supplement)

Scientific

Tub Natuke of Earth Currents.— Landeren, a French savaut, has for years past been making observations on the nature and role of earth currents at the City of Tortosa, and some of his remarks thereon are worthy of note. Ho believes that he has discovered the existence of telluric currents produced by the wind : and he finds that the direction of the currents change during whole months at a time. From various experiments with aerial lines, a Mascart electrometer and galvanometers, he obtains the result that when teleuric current and the wind are both in the same direction, or if the their directions form is under a right angle, the deflections are of a different sign. He concludes that the potential of the telluric current is very feeble ; and that the wind electrifies the earth, rather than the wire, and develops in the earth a current of the same direction as itself flowing through the soil over a large cross section. While upon this subject we may mention a published report from America (for the truth of which, of course, we cannot vouch) to the effect that Mr. Edison is occupying his mind with the problem of utilising earth currents for telegraphic purposes. How is to do it without the use of aerial wires is one of the mysteries of the report in question.— Engineering. Microbes of the Soil.—The value of the action of microbes in the soil would not be questioned by anyone who had given the mutter ■ sufficient thought. But to establish a conclusion by means of experiment always commends itself to the scientific mind. M. Laurent has made & series of comparative experiments in order to ascertain the influence of the microbes on vegetables life. Seeds of buckwheat were sown in four different kinds of mould. In the first flowerpot natural mould was employed ; in the second the same earth sterilized and theu inoculated with bacteria of the soil; in the third simply sterilized mould; and in the fourth sterlized mould with the addition of chemical manure. Precautions were taken to prevent contamination of the four receptacles. The production of wheat in each of the pots respectively was in the proportion of 04, 96, 23. 66. In all the experiments the third series was inferior to the others. The value of microbes in soil rich in organic detritus seems tlierebv to be proved.—Lancet.

A New Binding.—Yet another application ha" been found for metal, which is now being substituted for cardboard in bookbindmsr. This novelty is known as the "British Pellisfort" binding, and it consists in the use of thin sheet metal for covers. The metal is specially prepared, and the cuver maybe bent and straightened again without perceptible damage. It may, in fact, be safely subjected to such treatment as would destroy ordinary covers. The metal is, of coarse, covered with the leather ixsually - employed iu bookbinding, and the finished book presents no difference in appearance except in the greater thinness of the cover. It is well adapted for Bibles, Church Services, and other similar publications.