Scientific.

Waikato Times, Volume XXIX, Issue 2343, 16 July 1887, Page 2 (Supplement)

Scientific.

A Gkkat Bam.oon". —The captive balloon proposed by M (1. Von for the French Exhibition in ISSb will have the enonnoiiH volume of 00,000 cubic metres. The maximum altitude will be possible to take 100 passengers, a winding engine of OdO horse-power being employed. In the construction of this balloon, the following point is of some interest : The surface of the balloon must always be tight, in order to prevent the damage which otherwise a strong wind might cause. To preserve tightness, notwithstanding variation in temperature, another small balloon is placed inside the laree one, and the volume of this small balloon, winch is filled with atmospheric air, can be increased or diminished by pumping in or exhausting air by means of an air-pump, worked by an electric motor on the car, the current being supplied by a twin cable from a dynamo on the ground.— English Mechanic.

CONVERSION OF I[KAT INTO El.KCTlllctty. - Herreu Herghau-sen and Nernst have discovered a direct mode of transferring beat into electricity. It consists in placing a thin slip of metal in a magnetic field and maintaining its two ends at different temperatures, when a difference of potential is found between the two opposite sides of the slip. The direction of the current is reversed by reversing the direction of the magnetic field. The effect is, however, very slight. With a square plate of bismuth, measuring 5 centimetres on each side and ‘2 millimetres thick, a field of force represented by 5000 C- G. S. units, and a difference of temperature caused by placing a mica plate against two sides of the bismuth, one dipping in cold water and the other heated by a gas flame, the resulting difference of potentials was only' 0.00125 volts. With iron instead of bismuth the current is in the reverse direction. — Engineering. CitiLnitK.v'.s TicF.Tir. — It is gratifying to learn that the importance of proper attention to the teeth of school children—a subject on which we have more than once commented—is coming to he more fully reeognised by managers of schools. Thus, at the North Surrey District School, Mr Henry d. Moxom, L.D.S., has, at the solicitation of tire managers, and with the approval of the Local Government Board, just delivered a popular lecture to the officers and senior scholars of the institution on the construction, function and means of preserving the teeth. This, we believe, is the first occasion on which an address of the kind has been given in a government school, and it offers an example which may' well he followed in other similar establishments.—Lancet. Tut: Migration of Hf.krings,— -A remarkable illustration of the puzzling migratory habits of the herring has just been observed on the south-west coast of Norway, at the so-called Jicderen. hetween the towns of Stavanger and Egersund. This district used to he one of the richest herring fishing grounds in Norway during the spring, but about twentyfive years ago the fish suddenly and completely disappeared from the coast Last month enormous shoals once more came under snore, first “striking land” at the same spot as in former times. The quality of the herring is exactly the same as it was twenty-five years ago, and the shoals were accompanied by numerous herring " whales. —Nature.

Mortality is Fkexck Rkovixuial Hospitals.—ln a recent publication relative to tile mortality of French provisional hospitals, Dr. Albert Reguard states that it is far greater than that of the hospitals of London or Paris. This is accounted for by the excessive number and faulty construction of the beds, by disregard of elementary hygienic principles on the part of the administration. and, above all, by the insufficiency of the food provided for the patients. Dr. llegnard, therefore, insists that, in all hospitals where the death-rate exceeds 13 per cent., improvement should be made in those particulars.—British Medical Journal. The Form of Liuhtxixu.—Some photographs o£ a recent thunderstorm are said to indicate that the normal form of lightning discharges between the clouds and the earth is that of an irregular spiral. This is highly important, as it shows us the necessity of having irregular spiral lightning conductors instead of straight ones, so that the irregular spiral lightning may find it easier to get down the lightning-conductor into the earth.— Court Journal.

“At all events,” said a young doctor, as he heard of another one of Ids patient’s death, “I can take life easy, if 1 am poor. ”

Ox one occasion Webster the American senator was on his way to his duties at Washington. He was compelled to proceed at night by stage from Baltimore. He had no travelling companion, and the driver had a sort of felon look which produced no inconsiderable alarm in the senator. “ I endeavoured to tranqnilize myself,” said Webster, “ and had partly succeeded, when we reached the dark woods between Bladensburg and Washington—a proper scene for murder or outrage—aad here, I confess, my courage again deserted me. Just then the driver turned to me, and, with a gruff voice inquired my name. I gave it to him. ‘ Where are yon going?’ said he. The reply was, ‘to Washington, lam a senator.’ Upon this the driver seized me fervently by the hand, and exclaimed, ‘How glad lam ! I have been trembling on my seat for the Inst hour ; for when I looked at you I took you to be a highwayman.”

A ciur.u in Madras wrs the means of forcing a score of ships to put hastily to sea. She is tho daughter of an astronmor of that place. He predicts the weather, and his calnlatious have proved remarkably accurate. He is known to have made only one surprising meteorological mistake in his lifetime. The air was clear, the sky was bright, there was not a cloud, not even a breeze to stir the topmast frondage of tho palms. The astronomer, in a contendedjfr.amo of mind, paced the room in the cupola of the observatory. Suddenly his eyes vaught the barometer. It was falling rapidly! Five minutes more—it was hilling with terrible rapidity A cylono was evidently swoop ing dowo on Madras ! He rushed to the wire which connected his observatory with the‘master-attendant’s’ office, facing the roadstead. “Cut or slip?’ was the astonishing order. Six hours after the utmost consternation hid prevailed and more than twenty ships had suddenly put out to sea. Then tho astronomer discovered that one of his children had pricked the bulb of uis barometer with a pin.

Oxe of the arguments adduced by the Irish Chief Secretary (Mr Balfour) iu favour of passing the Crimes Bill, now before Parliament, was that an Irish midwife, a Mrs Dillon, had refused to attend a woman in her confinement, her husband being a boycotted tenant. Mrs Dillon immediately instituted an action for slander against the Chief Secretary, and set out in her affidavit: —“ That the publication of said slanders by the said intended defendant has greatly injured my character, and interfered with me in the pursuit of my profession and calling, and greatly decreased my practice and emoluments, and exposed me to ridicule and contempt from my neighbours, who are, for the most part, Nationalists, and who are naturally indignant that my alleged unfeeling conduct should have brought discredit on the cause, and be made the main ground by ti.e said intended defendant for a hill for the coercion of Ireland.” “Truth” says:—l really do think that even if the law gives Mrs Dillon no claim against him, Mr Balfour ought to do something for this lady. Why not appoint her monthly nurse to the Chief Secretary for Ireland ? It would be a graceful act on the part of Mr Balfour, considering the injury which he has done her; and even if she was no other use to him, she might help to deliver him of his speeches, and perhaps even make them a little more lively.