Scientific and Useful.

Lake Wakatip Mail, Issue 1580, 11 March 1887, Page 4

Scientific and Useful.

BAFE DRINKABLE WATF.R. The wholesale potable waters are spring water, deep well water, and upland surface water from uncultivated laud. Bain water, collected and stored in the u«ual m inner, and surface water from cultirated land should be considered suspicions; and river water which is polluted by sewerage and shallow well water is dangerous. WOOD OIL. Wood oil is now used on a large scale in Sweden from the lefme of timber cuttings and forest clearings, and from stumps and roots. Although it cannot well be burned in common lamps, on account of the heavy proportion of carbon it contains, it is siid to furnish a satisfactory light in lamps specially made for it; and in its natural state it is the cheapest illuminating oil. There are some 30 factories engaged in its production, and tliey turn out about 40,000 litres of the oil daily. Turpentine, creosote, acetic acid, charcoal, coal tar oils, &c, are also obtained from the same material a- the wood oil. A CVBIOCB CAVE There is a strange cave in a mountain side in Nevada, in the United States. Broken ►hafts of arrows are to be seen sticking in the soft rock of the roof. How cime they there ? Many years ago a number of Shoihone Indians were driven into the cave by their fierce foes, the Utes; but so skilful and strong were their defence of this shelter that their assailants proposed piece. Accordingly a council of " braves " was held in the cave, and terms of piece were agreed on, which was to last fo long as a single arrow remained embedded in the rock above their heads; and then no doubt, the first cf these arrows were implanted in the roof. rUOI'AGATION OF VLIE3. Their particular ofiice appears to be the consumption of those dead and minute animals whose decaying myriads would otherwise poison the air. It was a remark of Linnwus that three flies would consume a dead horse sooner than a lion could. He doubtless included the families of the three tli>'s. A single fly, the yiturali.it tells us, will sometimes pro luce -0 000 larva-, each of whirl in a f-w days may be the parent of another 20,t>00, and t'ms the descendants of three flies would soon devour an animal much larger than a horse. HCMuIBINO THE TELEPHONE. Everyone who ba9 Ufed the telephone much knows how troubhsime ''cross talk" is at times. Indeed, in lines net more than ten miles in extent, if there be paralie e 1 wires, a tioid clear service is not to be thought of. In this regard, a curious discovery wus recently made by one of the speakers at the recent convention. He says that wlien it is found impossible to work two pa.alle'ed wires at the same time, if those using one of them will speak German or any other foreign tongue, while those in the other are speaking English they will have no trouble in making themselves understood. Canada's coal ani> iron resotjiubs. Canada is evidently not yet ripe for the development of her immense mineral resounvs. Some day, doubtless, she will do great things wiih her coal and iron. In the situation of her coal beds not only she, but the British Empire, is particularly fortunate. In the east she hus abundance of coal bordering on the Pacific. Not only in time may she he the source of the principal coil supply for the wbole Pacific Coast of America, bu" the value to the Empire in case of war of two so accessible coal supplies is patent. Tho coal areas of Canada are estimated at about one hundred thousand square miles. Of the Cape Breton field alone the total available coal is estimated at »00,000,000 tons. The bHsin of true and legitimate co*l of the best quality along the base of the Kocky Mountains from the .'' !i pinil'e! to the Peace river, is estimated at otJ.OOO square miles, while the Ptuific Coast area is estimated at about 11,000 square miles. In qu dity the Vancouver Island bituminous coals are found to be superior for all practical purposes to any coals on the Pacific coast. — London Times. OLD FSKSIAN TALACEB AT sr/sA. A large qumtity of relics, the results of the excavations carrie t on for a long time on the site cf ancient Susa by Mr Dieulafoy and his companions, have arrive 1 at the mus'mn of Louvre. They were brought to Toulon in the tramport from Bas-orah, and filed 215 chests, that weighed over W.OOO kilogrammes (nearly 40 tons). The chief contents are : First, two fragments of a frieze of enamelled earthenware adorned with lions in basrelief, from the principal entrance to the palace of Artaxerxes Mnemon. B >th fragments were over 13 feot high by nearly !J0 feet long ; second, a similar fragment of a fri<ze from the palace of King Darius Hystaspes, adotn.d with twelve figures of the loy»l bodyguard, the famous " Immortals." This piece is 11J feet high by nearly 10 feet long; third, two fragments of a staircase in same material; fourth, two fragments of terra cotta friezes, showing fantastic animals—they are together over 20 feet long by 6 high; fifth the capital of a pillar from the palace of Artaxerxes, representing a two-headed monster—it is over lo' feet high by 13 feet in width; sixth, a col'ection of cut gems, numberiu* about 300, which seem to date from the earliest period of the Susauids dynasty ; seventh, a largo number of arrowheaded inscriptions on stone or glazed oarth, mostly from Susi. TUE sEI-LESEL. It has been a popular idea for a long time that the mean level of the seas remains identical, without change or variition. The seas, irlluenced by both gratify and centrifugal force, have been consider*d as having taken up a position of equi ibrium in such a way as to give the earth the form of an ellipsoid of revolution. We know that a pendulum, when freely impended, always takes a vertical direction, being attracted by the mass of the earth; but we know likewise that tho vicinity of a rr.ountain prevents the pendulum from taking a position of equilibrium, or, rather, mod lies tho other very scniibly. It attracts the pendulum, us does the rest of the terrcst:ial mass, but its action is nectsarly quite feeble—not enough to be appreciable—and it has been found that tie pendulum takes a different position of iquilibiium fiom that which it would have in the absence of a mountain chain. In the same way the great continents are found to draw from their equilibruim of level the intervening oceans. Soigey, in 1843, and then Fischer, Listing, and Burns studied this question, and reached the conclusion that these attractions bavo an intensity such as to be able to vary the surface of the sea 1000 yards, with respect to the lerel of the mean ellipsoid. Continents attract masses of liquid to such a point that, if we suppose for example, the section of the ocean between Havre and New York to be spread out on a pi me surface, a vessel leaving the latter city would at first find hcrseif upon a liquid hill, which she would desceid in measure as she left the continent, and reach towards tbe middie of her trip, the bottom of a vail y, whose opposite declivity she would mount and reach the summit of anotier liquid hill, whose culminating point would bo Havre,