Scientific.

New Zealand Mail, Issue 368, 1 March 1879, Page 5

Scientific.

The other day (says the Ballarat Star) Mr. Pryor exhibited at the Corner his safety-cage, which he has made to Mr. P. Davies' order for the Lachlan goldfield ; New South Wales. The general opinion of experienced practical men who have examined the cage appeared to be emphatically in favor of Mr. Pryor's invention, and several pronounced it to be the best they had seen. It combines the quadruple catch or clip to arrest the descent of the cage, is roofed with iron laps opening upwards, and is fitted with an escapement key, by which the cage can instantly be thrown out of the suspendinggear, and cast upon the clips. By this means the miner, if he apprehends any danger from foul air, or any thing else below, can stop the descent of the cage, whilst he is amply sheltered by the iron roof from the gathering rope above, pending the engine-driver's reversal of the winding gear. Letters patent were granted by the AttorneyGeneral of Victoria on the 31st ult. to Paul Jablochkoff, of Paris, engineer, for his improvements in electric lamps, and in arrangements connected ' therewith for dividing and distributing the electric light. Electric lamps, says the Argus as usually constructed, have the carbon points placed end to end, and mechanism is provided for the purpose of maintaining them at a suitable distance from each other as they are consumed, but by this invention all such mechanism is dispensed with, the carbon sticks being placed parallel to each other, and the material in which they are embedded being consumed simultaneously with the carbon. The light can also be colored, divided, and varied. Letters patent were also granted at the same time to Kennard Knott, of London, for two inventions concerning the preparation of and subsequent preservation of meat. In order to prepare the meat for preservation it is first subjected to a temperature of about 50deg. Fahrenheit for six hours, and then reduced gradually to 30deg., at which, point it is kept in a pure dry atmosphere," special provision being made for the preservation of a current of pure dry air at this temperature. An application by Messrs. Benny and Roberts, of Bathurafc, for letters patent for an invention for grinding quartz and other tailings, and amalgamating the gold extracted therefrom, was granted with certain restrictions. Mr. Waters conducted the first three cases, and Mr. Hingston the last. Under certain conditions the electric light is not an unmixed good, as may be seen by the following extract from the London Times. At The Times printing office, where the light is in use,'we have not heard of any complaints such as that contained in this letter. Professor Tidy, of the London Hospital, says :—" I have made a point of remaining in the neighborhood of the electric light for at least three hours, in order to observe its effects upon me after being exposed to its'action for some time. Eor a time nothing struck me except the intensity of the illumination, and the darkness beyond. But before long my eyes became entirely blinded to all rays except the blue ; and as a result everybody and everything appeared of a ghastly blue tint. Eor hours after I returned home the blue rays hauuted me ; but what was worse still, I suffered from what I am rarely a sufferer from—an intense headache, especially seated about the region of the the eyes. As a molical man lam convinced that whatever may be the advantage of the electric light as an illuminant for large outdoor spaces, it can never be used as a room illuminant, or even as a general street illuminant, with advantage, save to the medical profession generally and to ophthalmic surgeons in particular."

The microphone as a thief catcher has proved very useful to an English resident in India, who found his store of oil rapidly and mysteriously diminishing. He fixed a microphone to the oil cans, and after the house had been closed for the night, sat up to await the result. Very shortly he heard the clinking of bottles, followed by the gurgling sound of liquor being poured out, and running down stairs he caught his bearer in the act of filling; small bottles with oil, for easy conveyance from the premises.