Page:Popular Science Monthly Volume 1.djvu/528

512 propagation of worms which destroy the roots of the vine. He would thus do away not alone with the vines, but also with the vanity of the French, for, says the Saturday Review, "it is impossible to conceive that vanity could remain in a nation whose salvation had been effected by so humble and earthy an instrument."

many places in England they have for several years been using a safety-valve for steam-boilers that appears to be an absolute safeguard against explosions from low water. The valve is entirely within the boiler, and so rigged that when the water falls to a certain point the valve opens and a jet of steam is discharged upon the fires, the valve closing again when the water in the boiler is restored to its proper level. Being beyond reach, the valve cannot be tampered with, and, having its working-parts above high-water level in the boiler, it is not liable to get out of order from corrosion. Where these valves have been used, they have proved to be perfectly efficacious as a complete safeguard against explosion and collapse; and they are most highly spoken of, not only by steam-users, but also by inspecting engineers of boiler-insurance associations.

greater the specific gravity of a gallon of oil, the greater will be the amount of light obtainable from it; or, in other words, a gallon of heavy oil, burning with a flame of given size and luminosity, will last longer than a gallon of lighter oil, burning in the same manner. The light oil is more volatile, passes off into vapor, and is consumed more rapidly; thus the most dangerous oils are the least economical.

the Jardin d'Acclimatation at Strasbourg is a machine contrived for the fattening of fowls. The fowls are placed in a kind of dove-cot ranged in five different stages, each stage holding forty-two birds, which are separated from each other by vertical partitions, and which are so secured that their head and wings alone remain free. The "feeder" stands in front, and, taking the head of the bird in his left hand, forcibly introduces down its neck a quill which is in communication, by means of a hose of India-rubber, with a kind of reservoir full of the food beneath. The operator presses with his foot upon this novel species of bellows, and a dial placed opposite to him registers the exact amount of food to a fraction of a cubic inch. The amount of this singular dose differs according to the age and species of the patient, as well as to the degree in which it is desired he should be fattened. In eighteen days a fowl can be brought to the point of fatness desired, and in certain very favorable cases the weight has actually been doubled in that time.

Annual Meeting of the American Association for the Advancement of Science, which it was expected would be held in San Francisco, is to take place at Dubuque, Iowa, commencing on Wednesday, August 21st.

instance of tolerance by the human system of the excessive use of tobacco is afforded in the case of M. Klaes, of Rotterdam. This gentleman, who was known as the "King of Smokers," has just died, in his eightieth year, and is said to have consumed during his long life more than four tons of tobacco. The ruling passion was apparent in the will of the deceased, and in his eccentric request that his oak coffin might be lined with the cedar of his old cigar-boxes, and that a box of French caporal and a packet of old Dutch tobacco might be placed at his foot, and by the side of his body his favorite pipe, together with matches, flint and steel, and tinder.—Lancet.

the hand into a finger-glass until the water in it is warmed one degree. An amount of energy is withdrawn from that hand sufficient to project that water to a height of 772, or, if the degree be centigrade, to a height of 1,390 feet above the earth's surface—three times the height of St. Paul's.—Tyndall.

is easily joined and made as strong as an original fabric, by softening it before a fire and laying the edges carefully together, without dust, dirt, or moisture between. The edges so joined must be freshly cut. Tubing can be made by joining the edges of a sheet of India-rubber round a glass cylinder, which has previously been covered with paper. After the glass is withdrawn the paper is easily removed. Sift flour or ashes through the tube to prevent the sides from adhering from accidental contact.

a note to the Paris Academy of Sciences, on the influence which changes in barometric pressure exert upon the phenomena of life, M. Bent describes the effects produced by exposing small animals to various degrees of atmospheric pressure. He has found that, up to a pressure of two atmospheres, sparrows die when the air in the receiver contains 25 per cent, of carbonic acid, but that, above this limit, and below a pressure of ten inches, this law does not apply.

the recent meeting of the French Departmental Learned Societies, held at the Sorbonne, gold medals were awarded to M. Grandidier, for his geographical, geological, meteorological, and botanical works, in particular of the island of Madagascar; and to M. Houzeau for his discoveries respecting ozone, which he is enabled to produce in large quantities.