Bronzing Liquid.-Dissolve 10 parts aniline red and 5 parts aniline purple in 100 parts of 95 per cent. alcohol, in a water-bath ; then add 5 parts benzoic acid, and heat the mixture until the greenish color changes to a light bronze-brown. This liquid, when brushed upon metal, leather or wood, produces a beautiful bronze effect.Bayer. Ind. u. Gewerbeblatt. C. Precaution against Fire-damp.-The connection of mining explosions with low barometric pressures has long been noticed. In the colliery of Seraing barometers have been lately placed near each of the ventilators, with directions to give the ventilating fans 75 turns per minute in fine weather, 80 turns in changeable weather, and 85 turns in stormy weather.-L'Echo Indust. C. Alcohol in Animal Tissues.-M. J. Bechamp finds that alcohol may be detected in a large variety of animal tissues, even during life, as well as after death, in such quantities as to throw great doubt upon the evidences of alcoholic poisoning which have hitherto been regarded as conclusive. While agreeing with Pasteur, in most of his views as to the nature of ferments, he thinks that the bacteria which appear in the putrefaction or other alterations of animal tissues do not come from atmospheric germs, and he recounts a number of experiments which seem to confirm his views.-Am. de Chim. et de Phys. C. Utility of Solar Boilers.-M. Abel Pifre describes a variety of modifications of Mouchot's apparatus, adapted both to domestic and to industrial use. He thinks that they are of especial importance in connection with the projected railway to Central Africa. The Barbary figs, which are very abundant, yield about 25 per cent. of alcohol, more than the sugar beets. A single solar boiler, with a reflector of five metres diameter, can distil, without cost for fuel, 200 litres (52.8 gal.) of this alcohol per day, the raw material costing nothing, and the refuse being valuable for the food of cattle. The importance of this result becomes evident upon considering that Algiers imports every year more than 30,000 hectolitres (792,500 gals.) of alcohol, and that it will need to import still more for the manufacture of its wines, which require the addition of alcohol in order to bear transportation. Pifre is now experimenting upon the conversion of solar heat into electricity, and of the electricity into mechanical work, by the intervention of a Gramme machine.—Mem. de la Soc. des Ing. Civ. C.. Phosphorescent Lighting. Dr. Phipson takes sulphide of barium, or some other substance which is rendered phosphorescent by the solar rays, and encloses it in a Geissler tube, through which he passes a constant electric current of a feeble but regular intensity. He claims to obtain in this manner a uniform and agreeable light, at a cost lower than that of gas.-Les Mondes. C. Transparent Gold.—If a solution of gold in aqua regia is neutralized by carbonate of soda, and a solution of oxalic acid is added, the gold is precipitated in a brilliant yellow powder. On examining this precipitate by the microscope the flakes are found to have a triangular or hexagonal form and to be translucent, the color of the transmitted light depending on the thickness of the crystals.—Les Mondes. C. Transplanting Eels.-The French engineering corps has been experimenting for some years past upon the transport of young eels by railway, in order to supply various streams in the different departments. Very little care is necessary except to avoid shipment when the temperature descends below the freezing point. They have already successfully transplanted about 1,500,000 eels.-Ann. des Ponts et Chaus. C. Planetary Arrangement.-In recent papers before the French Academy MM. Gaussin, Faye, Chase and Schötel have discussed various indications of law in the arrangement of the planets and some of their bearings upon the nebular hypotheses of Laplace and Hershel. The indications which were given by Prof. Chase were the closest and most striking, furnishing numerical evidence of a projectile force connecting the solar system with the fixed stars.-Comptes Rendus. C. Influence of Light on Size of Leaves.-M. Ch. Flahault, in the Annales des Sciences, brings forward additional observations to support his view that under equal conditions the leaves of plants of the same species are larger in proportion as we go nothward, these relatively higher dimensions being due to the duration of light of relatively feeble intensity. In cases where the chlorophyll is formed in the absence of light, it must be formed at the expense of the materials stored up in the tissues. The importance of these reservoirs of nutriment is still greater in the case of flowers. Thus, of hyacinths, both red and blue, M. Flahault found no difference in the color of the flowers grown in the light or in the dark, the color being manufactured from the stores of material in the bulbs. New Welding Process.-Krupp has recently taken out a German patent for a new process of welding tubes and tires. He draws the tube on a pair of ordinary rolls and heats the whole length of the portions which are to be welded in a portable fire-box, into which air is blown so that the heat is directed against the weld. After the necessary heat is obtained the rolls are set in motion and the place which is to be welded is repeatedly drawn through them.-L'Ingen. Univ. C. Accuracy of Glass Gauge-tubes. In his experiments upon compressibility Amagat employs for manometers glass tubes of about 1 mm. (0-4 in.) internal diameter, and 10 to 12 mm. (39 to 47 in.) exterior diameter. He has subjected them to severe and repeated tests, and finds that they undergo no change, either in diameter or in length. Those which he has employed for more than a year, under powerful and prolonged pressures, give the same results to-day as when he gauged them for the first time.-Comptes Rendus. C. Stability of Bramante's proposed Cupola for St. Peter's.M. Alfred Durand-Claye has examined, both theoretically and experimentally, the strength of the cupola which Bramante projected for the church of St. Peter in Rome. He finds that it would have been stable with materials which would resist a pressure of eight kilogrammes per square centimetre (113.8 lbs. per sq. in.). It is interesting to find that modern scientific methods thus confirm the inspirations of a skillful architect whose numerous domes were projected by feeling rather than by mathematical knowledge.—Bull. de la Soc. d'Encour. C. Profit of Public Works.-M. de Labry has written an essay, in which he discusses the various advantages of public improvements to invested capital, to adjacent regions, and to the government, showing that the dividends to stockholders and the direct revenues of government constitute only a small portion of the benefits conferred by increased facilities for travel and the transportation of merchandise. He thinks that both self-interest and duty should prompt the inhabitants of regions which have been well developed to contribute towards the opening of new districts. Even if the contributions appear to be sunk, the increase of trade and of general prosperity will, almost without exception, amply repay all the outlay.-Ann. des Ponts et Chauss. C. The Steam Yacht "Anthracite " and the Perkins System of High Pressure Steam. By Maj. Geo. Deane 228 Coal Gas Engineering. By Robt. Briggs, C.E........................... The Photophone. By Alexander Graham Bell... Paraffine as a Protection to Wood and Iron. By Dr. Eugen Schal. On the Proper Form of Lightning Conductors. By William Henry Preece...... A New Powerful and Constant Battery without Acid. By Emile Reynier......... The Temperature of Flames............. Book Notices............ Franklin Institute....... 233 237 249 ... 252 254 ........... 257 270 272 275 276 282 ITEMS. Solidification under Pressure, 248. Atmospheric Absorption of Ultra Violet Rays, 236. Successive Transformations of Photographic Images, 253. Influence of Electricity on Vegetation, 280. Boiler Scale, 280. Electro-Dynamic Paradox, 280. Decomposition of Carbonic Anhydride by Magnesium, 281. Celluloid Stereotypes, 281. False Meteorites, 281. Electric Fishing, 282. Contact Electricity... ......... 282 Philadelphia: FRANKLIN INSTITUTE, 15 South Seventh St. ESTABLISHED 1853. HOWSON & SON'S OFFICES FOR PROCURING United States and Foreign Patents AND PROSECUTING PATENT CAUSES. HENRY HOWSON, Engineer and Solicitor of Patents. CHARLES HOWSON, Attorney-at-Law and Counsel in Patent Cases. Principal Office, 119 South Fourth Street, Philadelphia, Branch Office, 605 Seventh St., Washington, D.C. Authors of "The American Patent System," "Our Country's Debt to Patents," "Answers to Questions of the State Department Relating to Patents." Also, "Brief Treatise on Patents," published by Porter & Coates. Jan. '80 1 yr. of a RUDOLPH M. HUNTER, M.E., C.E., CONSULTING ENGINEER & SOLICITOR -OF United States & Foreign Expert in the Trial of Patent Causes. Examinations in regard to the Validity and Infringement of Patents. Offices, Rejected Cases a Specialty, 901 Walnut St., Dec.. '79 1 yr PHILADELPHIA. |