Scientific and Useful.

Western Star, Issue 983, 19 September 1885, Page 1 (Supplement)

Scientific and Useful.

Experiments at Woolwich Arrenal laboratory have provad that damp or even wet guncotton can be exploded if sufficient dotonot.ve force bo supplied. '“Compier-sed air baths have been found to bo extremely efficacious on the Continent in the treatment ot various chest affections, including some diseases of the heart. In cases of chronic diarrhoea, for which a diet of raw meat is recommended, the following formula may be found useful. Take be.-f reduced lo j ulp, mix this with ruin, brandy, or whiskiy enough to make into a soft mash, to which add, according to taste, either salt or sugar. .KOUMISS. The following is said to be a good recipe for the preparation of koumiss:—Powdered sugar of milk, 100 parts ; glucose (prepared from starch), 100; cane sugar, 300; bicarbonate of potassium, 36; common salt, 33. Dissolve these ingredients into 600 parts of boiling fresh whey of milk, allow the solution to cool, then add 100 parts of rectified spirits, and afterwards 100 parts of strained fresh beer yeast. Btir the mixture well and put into half pint bottles. The bottles must be well corked and kept in a cool place. For the preparation of koumiss add two or five • tablespooufuls of this extract to a quart of skimmed, lukewarm milk, contained in a bottle of thick glass, cork well, keep the bottle for half a diy in a moderately warm room, aud afterwards in a cool cellar, shaking occasionally. SELENIUM SUNLIGHT MBASUSER. M- Morize, of Rio de Janeiro, has invented an ingenious selenium apparatus for measuring the relative intensities of the rajs of the sun at d fferent altitudes above the horizon. It consists of a selenium cylinder prepared according to the plan of Professor Graham Bell, 38 discs of copper being insulated from each other by smaller mica discs, and the edges filled in with selenium. It is insulated by glass supports inside a glass envelope, from which the air has been exhausted. The vessel is elevated in a place where surface reflection doe< not reach it, aud the axis is placed parallel to the axis of the earth, so that the rays of the sun fall normally on the selenium cell, and illuminate the same surface. Its position can be altered to keep up this condition from day to day. A constant current traverses the selenium aud a galvanometer in circuit with it. BIG BLASTS. The mightiest of gunpowder blasts in connection with railway works, if not the very greatest blasts ever exploded, was that by which Sir William Cubbitt blew away, with one charge of 19,000 pounds of gunpowder, the entire mass of the Round Down Cliff, which rose to the height of 350 feet above the level of the sea within a few miles of Dover. This monster blast, fired by galvanic electricity at several points instantaneously, at once heaved off from the cliffs a mass of more than a million tons of chalk, which rolled down upon the beach—the dislodged stuff covering a space of more than 15 aces, which may still be seen by the traveller al mg the South-Eastern Railway, stretching towards the sea near the western base of the wellknown Shakespeare’s Cliff. By means of a similar blast on the Londonderry and Coleraine Railway a hill was thrown into the sea by a charge of three thousand pounds of gunpowder, and thirty thousand tons of material were thus instantaneously removed from the line of the works. NATUBAL GAS IN PITI3BUEG. Natural gas is now conveyed to Pittsburg through four lines of s|in. pipe and one line of Bin. A line of lOiu. pipe is also beiug laid. The pressure of the gas at the wells is from 150 to 230 pounds to the square inch. As the wells are on one side 18 and on the other about 25 miles distant, and as the consumption is variable, the gressure at the city cannot be given. Greater pressure m ; ght be obtained at the wells, but this would increase liability to leakage and bursting of pipes. For the prevention of such casualties safety valves are provided at the wells, permitting the escape of all superfluous gas. The enormous force of this gas may be appreciated from a comparison of say 200 pounds pressure at the wells with a 2 ounce pressure of common gas for ordinary lighting. The amount of natural gas now furnished for use in Pittsburg is supposed to be 25,000,000 cubio feet per day; the lOin. pipe now laying is estimated to increase the supply to 40,000,000 feet, The amount of manufactured gas u=ed for lighting the same city probably falls below 3,000,000 feet. About 50 mills and factories of various kinds in Fittsburg now use natural gag. It is used for domestic purposes in 200 houses. DUST EXPLOSIONS. Speaking about dust explosions, says the Milling World, a case from Germany is woi thy of notice. A sack of flour, faldug down stairs, opened and scattered the concents in a cloud through the lower room, where a burning gas flame set fire to the dust, causing an explosion which lifted a part of the roof off the mi l and broke almost all the windows. There can be no doubt that the majority of dust explosions are, like mine disasters, due to open lights, and as this danger can be practically avoided by the use of the incandescent electric lights, there really seems to be no valid rcamn why it should be introduced more generally, aS those establishments which have Used it express themselves in its favour. No matter how o'her lights are guaidcd, an absolute safety as long as the globes are intact, is offered only by the incandescent lamps, where the atmosphere has no access whatever to the flame. The above instance teaches also how little is necessary to start an explosion iff the cleanest mill, so long as open lights are used ; how much greater must the danger be in establishments where the air is constantly charged with dust, and where cleanliness is looked upon as of minor importance. LEARNING TO ?LY. A Burning that a machine for the purpose of flight has not only bseu iuvented but perfected, and will carry us smoothly away at our own discretion, much yet remains to be accomplished, for we must learn how to use the new’y acquired power which would otherwise be only a source of disappointment and anger. It is for all of us now per ectiy easy to walk. We do it so automatically that mentally we are conscious of uo effort. But it [is because we learned to walk in infancy. If We had never learned, we should not only be unable to walk, but we could not even stand erect, for in either case we are at each a Oinent engaged in a complicated series of necessary balancing movements, but of whose existence we are commonly not conscious, this will be our condition in aerial travelling. The power aud the perfect machine will be useless until we have learned how to use them with confidence. A beam which aff rds an easy path becomes aim st impassable when It 11 ec oss a mountain chasm. Rising from the ground must of nscessity be at first a matter of apprehension, and even terror. The confidence of habit will alone make it enjoyable. We creep before we walk.— fiomiijlo dmerlean.