Scientific.

Waikato Times, Volume XXVIII, Issue 2292, 19 March 1887, Page 2 (Supplement)

Scientific.

A Luminous Rifle-Sight.—The British War Office authorities have had a new invention in the shape of luminous riflesights under trial for the past six months, and have now given an order for a supply. The difficulty of sighting rifles in the dark iu 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 foresight and another over t.he rear-sight when used at night in reply to an enemy's fire, forming two luminous sight'. There may be two sides to the question. Would not troops using the luminous sights preseut a bright target to the enemy in the shape of an army of glow worms ?— Broad Arrow.

A Curious Contention'. —A French physician contends that groaning and crying are two grand operations by which nature allays anguit-h ; that those patients who give way to their natural feelings, more speedily recover from accidents and operations than those who suppose it unworthy in a man to betray such symptoms of cowardice as either to groan or cry. He tells of a man who reduced his pulse from 120 to GO in the course of a. few hours by giving full vent to his emotion. If people are unhappy about anything, let them go into their rooms and comfort themselves with a loud boo-hoo, and they will feel 10!) per cent, better In accordance with this the crying of children should not be too greatly discouraged. What is natural is nearly always useful.—American Hoimepathist.

Nuw Use for Electricity'.—ln a lecture at the Royal Institution London Professor Oliver Lodge has endeavored to show" that electricity might be employed to clear the upper atmosphere of great cities of the overhanging clouds of dust and smoke. He exhibited bell jars filled with dense smoke, and rendered them clear in an instant by an electrical discharge from a friction machine. A similar discharge of electricity on a large scale into the dust aud smoke-laden air over London would, ho thinks, produce a like effect, and he is desirous of making experiments of sufficient magnitude to test the correctness of this view.

Dkltc.vtb Piiotoc! hal'i ty. — German photographers have succeeded in pliotogragraphing a projectile in the course oi: its flight, and soino of the photographs show the head of condensed aiv which, precedes every shot. It is this " head which prevents even skilful riflemen from hitting an empty egg shell when hung- on a long thread. The air blows the shell oat of the way of the bullet. An* Interesting- Inquiry. — Dr. Sohwcinfurth has, in the interests of science, addressed to all Europeans, especially physicians, residing in Egypt, an inquiry as to whether, so far as they ar-s aware, families of Northern origin seuling in Egypt d.\ or do not, die out within three generations, or whether the race is capable of being perpetuated beyond that limit.

Coldest Tj-vo;: rx the World.—The coldest place known is at Workhojanck, Siberia, observations made during 1885, giving tlio mean temperature of the year an 1 degree Fahrenheit, of the month of January as 50 below Z"ro, and the lowest temperature the >«iino month as 00 below.