OLLA PODRIDA.

New Zealand Mail, Issue 787, 1 April 1887, Page 6

OLLA PODRIDA.

A LUMINOUS RIFLE-SIGHT. The War Office authorities have had a new invention in the shap of luminous rifle-sights under trial for the past six mouths, and have new given an order for a supply, The difficulty of sighting rifles in the dark in warfare has been ingeniously overcome by the use of this invention. A small bead coated with luminous paint is clipped on to the rifle over the fore-sight and another over the rear-sight ■when used at night in reply to an enemy’s fire, forming two luminous sights. Tnere may be two sides to the question. Would not troops using the luminous sights present a bright taraet to the enemy in the shape of glow worms’ —Broad Arrow. AMERICAN NAVAL FAILURES. Secretary Whitney, who has now been at the head of the United States Naval Department for nearly two years, confesses in his new annual' report that he has been able thus far to do little more than discover the magnitude of the task confronting the man who essays to put the American Navy on a satisfactory basis. Although there is an apparent effort to make the tone of the document hopeful—not to say cheerful—it is difficult to select any phase of the report’s statements or conclusions which warrants anything but depression.—Engineering. PRINTING BY ELECTRICITY. The American Inventor, of Cincinnati, a large monthly journal, saye :—‘We print this month 8 issue for the first time by means of electricity. The Sprague motor is used and is an immense advance on any other kind of power. We are running four presses with a single motor, and it is quite a novelty in action. The motor is built in a ■very substantial manner, and there are no parts which wear rapidly even with ordinary care. The expense for repairs cannot amount to 10 per cent of that required for either steam", gas or hot air engines, _and we now see no reason why it will not give, for many years to come, as good results as at present.’ “ PETER THE GREAT.” How are the mighty fallen ! _ Most of us remember Sir E. J. Reed’s warnings of what was likely to befall us if wo did not reply to Russia’s Peter the Great with at least a Victoria the Greater, and now we are told that she has become a floating workshop at Cronstadt —all she was ever fit for. She was an imposition and a sham from the very beginning. Not more than half the money granted by the Imperial Treasury was ever spent on her. The rest went'where money generally does go in Russia—into various pockets that had no right to it. But do not let us fall into the mistake of thinking Ex uno diace omnes. The ironclads Russia is building now are of as good workmanship as ours or anybody else’s.—Army and Navy Gazette. PEARL FISHING BY ELECTRIC LIGHT. Amongst the more recent applications of the electric light must be reckoned it 3 use in the pearl fishery. Hitherto it has only been found possible to give a light to the depth of seven or eighth fathoms ; but it is expected that in the case of the steam yacht Chic, owned by Messrs Alley M'Lellan, engineers, Glasgow, light will be given at a depth of over 18 fathoms. The Chic has been fitted with a Brush dynamo for the purpose of suiting her for pearl fishing in the South Australian waters. The electric globe has not yet been fitted on board, as it is difficult to get glass strong enough to bear the strain of the great pressure which would be brought to bear upon it. The Chic is at present in the Gareloch, where she will remain until arrangements are completed for

the fitting up of the electric globe, when she will leave for her destination.—lron.

NEW PHOTOGRAPHIC APPARATUS. Mr W. J. Lancaster has just patented a clever apparatus to be used for detective purposes or ordinary portrait photography. The apparatus is enclosed in a watch case, which dpeus in the ordinary manner by means of a spring. As the case opens, a miniature lens is exposed for a moment, olosed again, and the thing is done. The sensitive plates to be used for the camera are miniature dry plates, and a store of these is to be carried by the operator in a specially prepared locket to hang on the watch chain. This miniature apparatus is said to be welcomed by the detective police It is statt-d that for the sake of experiment, accurate likenesses were taken of a large number of the persons who mixed in the crowd at the last Socialists’ meeting. — Amateur Photographer. THE FRENCH PRESIDENT’S SALARY AND PERQUISITES. M. Grdvy receives as President of the Frenchrepublic a yearly salary of 240,000d015, besides the following allowances : 20,000d01s for heating and lighting, servants and washing ; 60,000d01s for his entertainments and journeys; and 25,000d01s for the maintenance of his game preserves. With respect to the latter, it is worth while noting that the game is no longer sent to hospitals and barracks, as in former times, but is sold, exempt from the octroi duty, for the private benefit of the President. The cost of hia travels is always defrayed by the railway companies over whose lines he travels as a deadhead, and he has a free box at the Opera and all the theatres. The most perfect of official residences is provided lor him in the beautiful and commodious palace of the Elys4e. SPEED OF ENGINES MEASURE. The use of intermittent light to indicate the speed of engines or other moving bodies has teen proposed by M. Gustave Hermitte. His plan is to illumine a Giessler tube by the Bparks of an induction bobbin, giving a constant and known rate of vibration per second, say from thirty to forty, each vibration giving a corresponding flash of the Giessler tube. By optically arresting the moving objects at different points of their course, he proposes to obtain their speed. For example, if a disc of cardboard be made to revolve by clockwork at a uniform and known speed, say, one turn per second, and if it be lighted by the Giessler tube giving thirty flashes per second, we shall see the disc thirty times during one second, or, in other words, while it makes one revolution ; and if there be a visible spot on its surface, thirty spots will be seen. If the disc turn ten times per second, the succession of images will disappear ; owing to the persistence of impressions on the retina, the disc will appear to be immovable, and we shall see three spots on its circumference occupying fixed positions. If the number of turns of the disc is equal to the number of flashes of the tube the disc will be seen to be immovable. A printed page revolved in this way could be read as if it were fixed,—English Mechanic.

WOLVES HERDING CATTLE.

A few days ago, while hunting antelope on the divide between Horse and Adobe creeks, I came in sight of a band of wolves, thirty or more, which were closely herding about two hundred head of range cattle. My curiosity to learn their object induced me to remain a couple of days in seeing distance to observe their actions. When my attention was first drawn to the wolves they were ogether in the rear of the cattle, but very soon they separated and surrounded the gradually outspreading herd and chased the animals together. They wouid then await the motions of an apparent leader, who would run into the bunch, cut out a calf, when the the rest would rush to him, help throw and hastily tear out its entrails. Thus mangled they would leave it, separate, and run swiftly to surround the now feeing cattle, again round them up, single out another calf, throw and leave it in a dying condition. If any of the older animals hung back and showed fight they would be instantly hamstrung. and left thus disabled. In no instance did the wolves seomed disposed to farther mutilate these older animals. This man'euvrin< was repeated time and again until the wolves must have satiated their thirst for blood. Then these varmints seemed to be inspited by the teaching of the author, ‘ music hath charms to sooth the savage breast,’ for they would raise a hideous howl, which effect on the cattle was not satisfactory, for they would trail out and try to get away, when they would again be chased close together. and held to await further action. How large this bunch was when the wolves first gathered them together I have no m ans of knowing, but am satisfied that the wolves and cattle will be inseparable until hhe calves are all killed. Then I think they will gather another and again another bunch and kill all the young. I counted in two days eleven calves, some yet alive, with their entrails protruding from their sides, besides seven large and older ones with their hind legs rendered useless.—Letter in Elbert, Col., Tribune.

A RARE CAUSE OF DEATH WORTH NOTING. The Medical Journal gives the following interesting account of a death from acute rheumatism : -- » i he case of the late Gen. Logan appears to be one of those rare ones in which acute rheumatism causes a rapid and fatal. issue. On December 12th Dr. J. H. Baxter of Washington, D.C., was called to see him, and found him suffering from acute rheumatism, involving the right wrist. He improved until the 17th, when he had a relapse, the hips, ankles, feet and both wrists becoming involved. Brain symptoms also appeared at this time. Though there was some temporary improvement on the 21st and 22nd, the symptoms on the whole became gradually more severe, the intervals of full consciousness shorter, until early on the morning of December 26th, when he became comatose. He died twelve hours later. • The cerebral symptoms were those of congestion of the brain. * Acute rheumatism is so rarely a cause of death that some complication is expected,

and almost always found, in fatal cases. When death does occur it is, as a rule, with cerebral symptoms, as was the case with Senator Logan. Such symptoms are much more liable to develop in persons whose nervous system has been subjected to tremendous strains, as well as to the toxic effects of narcotics and stimulants. *

‘No doubt the exhausting political and literary labors of the deceased had made it possible for the rheumatic poison to attack and paralyze his nervous centres, thus bringing to a fatal issue a disease that in 97 per cent of cases is perfectly free from danger to life.—Medical Journal.

A PERPETUAL GRAVITY MACHINE.

Dr. Wini am H. Gray of West Fall*, a small village iu the eastern section of Frederick county, has been exhibiting in Frederick during the past lew days the model, of a machine on which ho lias been exercising his inventive genius for many years, and in the success of which he claims to have found the long-sought solution of a great scientific problem. The machine is called by its inventor ‘ The Perpetual Gravity - power Machine,’ It consists of one wheelj twentysix inches in diameter and eight inches in width across the rim, made df iron and steel. Inclosed in this wheel is a series of works, the wheel being keyed to a steel axle and bearing in brass boxes, which are set in a woodeu frame. lb weighs about sixty pounds, and furnishes thirty pounds of power from the journal, which is three quarters of an inch, turned down to one-quarter of au inch bearing. The motive principle is that of weights sliding to and fro from the centre of the wheel. There are two inner wheels, each twenty-two inches in diameter, between which the weights are placed. These weights are so arranged that in descending they give a sufficient momentum to carry the wheel around continuously, and it is claimed that this revolution will be kept up until the parts are worn away by friction. Dr. Gray has, with a belt attachment to his machine, been running a clock, out of which the springs have been taken, for several months almost continuously. He states that with ah 8-foot wheel his machine will furnish 200 horse power. Explaining its working, the inventor, in order to show that there was no electric or hidden magnetic influence used in propelling the wheel, lifted the journals from the brass beariug and set them in wood, aud in the meantime the wheel kept up its steady and uninterrupted revolutions. Dr. Gray has appeared before Magistrate Besant, and made affidavit as to his invention, claiming its power to be derived from the attraction of gravitation, etc. The machine attracted a good deal of attention here, and it is thought by many that at least a new means of furnishing motive power has probably been discovered. —Frederick Md., Corr. Baltimore Sun,