Oct. 1st, 



■•] 



SCIENTIFIC NE^VS. 



173 



amalgamation of ores to Spain ; the chronometer, the steam- 

 engine, the fly-shuttle and loom, the general development 

 of iron — by rolling-mill, hot blast, and smelting-furnace — 

 the stereotype, illuminating gas, and the Bessemer process 

 of steel-making, to Great Britain; while the United States, 

 youngest of all, claims the cotton-gin, steamboat, reaping- 

 machine, sewing-machine, type-casting, the electric tele- 

 graph, vulcanised rubber, the friction match, the steam 

 fire-engine, the street railway, and revolving fire-arms. 



Soldering Cast Iron with Tin. — Many ornamental 

 articles are made of cast iron, variously decorated, but the 

 smaller specimens of this kind break very easily if carelessly 

 handled. The question then arises how to mend the broken 

 article, a question that has puzzled many, as it is so very 

 hard to unite firmly pieces of cast iron, because it has but a 

 slight affinity for tin solder, The soldering can be made 

 much easier by first cleaning the faces of the broken parts 

 from all impurity, unless the fracture is of recent occurrence 

 and the broken parts are perfectly clean. With a brass wire 

 brush, the faces of the fracture are thtn rubbed until they 

 appear yellow, and are so to speak " dry plated " with brass. 

 The surfaces are then tinned, just as brass is tinned, and 

 the parts can be soldered together without difficulty. — Dcr 

 Mctallarbcitcr. 



Why Snow Destroys Marble Statuary. — From the 

 Pharmaceutical Journal we learn that the results of the 

 examination of snow taken from different places in Munich 

 and its neighbourhood by Mr. Sendtner, would seem to 

 indicate not only that snow has a considerable faculty for 

 absorbing sulphurous acid from the atmosphere, but that the 

 absorption goes on continually for some time. Mr. Sendtner 

 ascertained that, on one day when snow fell, sulphurous and 

 sulphuric acids were present in it in fairly equal proportions, 

 but on the second day almost all the sulphurous acid had 

 been ozonised to sulphuric acid. In the vicinity of chimneys 

 and gas works the absorption would of course be greater. 

 This great absorptive power for sulphurous acid is con- 

 sidered of great practical interest as explaining the destruc- 

 tive action of snow on marble statuary. 



Definition of Scieinxe. — A contemporary remarks that the 

 present generation is crying out loudly for a scientific educa- 

 tion for the working-classes, to enable them to compete with 

 the better educated workers of other lands ; but there is a 

 marked difference of opinion as to what " science " means. 

 Sir William Hamilton defines science as "a complement of 

 cognitions, having, in point of form, the character of logical 

 perfection, and, in point of matter, thecharacter of real truth." 

 Herbert Spencer defines science as " a higher development 

 of common knowledge," and most scientific people agree 

 with the statement that science is, pure and simple, " or- 

 ganised common sense." The wider the definition the 

 better, but the definition adopted in some schools is peculiar, 

 and the results are disastrous to every attempt made to 

 organise the common sense of the unfortunate pupils, for 

 the system of " cram " is used under the sacred name of 

 science. 



The Motive Power of the World. — From a note pub- 

 lished by the Bureau of Statistics in Berlin the following 

 very interesting figures are taken. Four-fifths of the 

 engines now working in the world have been constructed 

 during the last five lustra (35 years). France has actually 

 49,590 stationary or locomotive boilers, 7,000 locomotives, 

 and 1,850 boats' boilers; Germany has 59,000 boilers, 

 10,000 locomotives, and 1,700 ships' boilers; Austria, 

 12,000 boilers, and 2,800 locomotives. The force equiva- 

 lent to the working steam engines represents in the United 

 States 7,500,000 horse-power, in England 7,000,000 horse- 

 power, in Germany 4,500,000, in France 3,000,000, in 



Austria 1,500,000. In these the motive power of the loco- 

 motives is not included, whose number in all the world 

 amounts to 105,000, and represent a total of 3,000,000 

 horse-power. 



Paper Roofing. — It is said that compressed paper pulp 

 hasbeenusedin America for the covering of roofs. The advan- 

 tages claimed are lightness, which obviates the necessity of 

 the present heavy frame support ; a toughness and elasticity 

 not possessed by slate, rendering breakage an impossibility ; 

 a singular power of resistance to intense heat or flame ; and 

 a readiness to receive nails, which bind it compactly to the 

 bed, and so closely together that high winds will not loosen 

 or cause them to shift, as is frequently the case with slate 

 tiling. The process of manufacture is very simple. The 

 mould is first prepared, into which the pulp is pressed 

 and allowed to partially dry. The crude tiles are then 

 dipped into a solution to harden their fibres and render them 

 waterproof. When thoroughly impregnated they are dried 

 by baking in an oven heated to a special temperature, then 

 coated with an enamelling mixture, upon which is sifted a 

 thin coating of fine sand, coloured according to the tint 

 desired, to fireproof them. They are subjected to heat a 

 second time, and are then ready for use. 



Meteorite in New York. — According to the Neiv York 

 Times, something resembling a meteorite struck the side- 

 walk in Brooklyn, at Troy and Fulton avenues. When first 

 seen it was said to have resembled a ball of about the size 

 of a man's head, but was broken into fragments by 

 the fall. The substance is of a bright vivid green and 

 porous. When first procured it was soft and plastic, taking 

 the impress of the fingers. After remaining over a day it 

 became brittle and friable. It resembles precisely in ap- 

 pearance the green deposit left on a battery. At first it 

 was thought that the lightning had struck a copper wire or 

 roof, had melted portions of it, and, oxidising it, had carried 

 it to a great distance. Analysis showed its probable me- 

 teoric source, as it gave with the reagents and the blowpipe 

 unmistakable evidence of the presence of cobalt and nickel, 

 which twin metals are always found in meteorites. There 

 were no traces of copper, and faint indications of iron. 

 From the quantity of the material it is thought that the ball 

 when intact must have weighed twenty pounds. Portions 

 have been sent to the Smithsonian Institution. 



Windmills for Electric Lighting. — Experiments are 

 being made at Cap de la Heve, near the mouth of the Seine, 

 on the production of electricity for lighthouse purposes by 

 means of the power obtained from windmills. The suggestion 

 to do so was made by the Due de Feltre, and it is a system 

 proposed by him that is to be tested. The wind works a 

 dynamo-electric machine employed in charging accumulators 

 of suitable capacity. The electricity so produced and stored 

 is to be used at will as a source of light. The system, if suc- 

 cessful, will have the advantage of involving only the cost of 

 putting up of the machinery. The whole question to be 

 ascertained is whether a sufficient quantity of electricity can 

 be stored to provide for the requirements of any particular 

 station when there is no wind to move the sails of the mill. 

 M. de I'Angle-Beaumanoir, a civil engineer at Paris, has 

 been authorised by the Minister of Public Works to make, 

 at the expense of that department, a trial of this system of 

 electric lighting at the La Heve lighthouse. The experi- 

 ments will in no way endanger or inconvenience navigation, 

 as the present machines are ready to be used should the 

 new system fail to work. 



A Long-surviving Fallacy.— We are told by the 

 Farming World, that an English experimenter finds that, 

 contrary to general opinion, the growth of ivy over a house 

 renders the interior entirely free from moisture ; the ivy 



