Progress of Invention. 315 



A new Blasting Powder. — Vast quantities of explosive material 

 are now used, in the operation of blasting ; and hence numerous 

 attempts have been made to discover new and better explosive com- 

 pounds than gunpowder. The efforts which have been made in 

 this direction have not, as the discovery of nitro-glycerine attests, 

 been without success. The dangerous nature of that substance, 

 however greatly limits its utility. Wilhelm and Ernst Fekleisen 

 have formed a compound which is in several respects superior to any 

 of the explosive materials hitherto used. It cleaves, rather than blows 

 into atoms : an important quality, especially when it is employed in 

 the coal mine. It does not ignite spontaneously, nor is it set on 

 fire by friction or percussion. Its combustion gives rise to no 

 opaque, nor suffocating gases, which makes it very valuable in the 

 operations of tunnelling. It has but one disadvantage : weight for 

 weight, it is twice as bulky as gunpowder ; but even this is in a 

 great measure compensated by the fact that it is one-half more 

 powerful. It is formed by thoroughly mixing nine parts by weight 

 saw-dust obtained from a light and non-resinous wood, or wood 

 from which the resin has been extracted, from three to five parts 

 charcoal, and forty-five parts saltpetre, and, if required to be quick, 

 one part ferrocyanicle of potassium ; the mixture being moistened 

 with one quart of water to every hundred weight. It is granulated 

 by stamping or crushing, and the grains may be polished in the 

 ordinary way ; this, however, will merely improve the appearance 

 without increasing the explosive power. This compound has been 

 termed Saloxylin. 



The Colours op the Stars. — The determination of the precise 

 tints of the stars is not only a matter of interest but importance ; 

 and an instrument for this purpose has recently been invented. 

 The object proposed by the inventor was to compare the tint of the 

 star to be examined with that of a solution, the colour of which is 

 known. For this purpose, a platinum wire is rendered incan- 

 descent by means of two elements of a Smee's battery ; and the rays 

 of the artificial star, thus produced, are made to pass through small 

 phials, filled with solutions of known tints, and attached to a drum 

 which has radial openings, and is capable of revolving, after which, 

 they pass into the objective of a small telescope. The artificial and 

 the real star are compared ; the drum being turned until the rays 

 from the incandescent platinum appear of the same tint as those 

 from the star. When the tints are the same, it is known that the 

 proper solution has been used, and the tint of this solution being 

 known, the colour of the star is found. 



Magnetism and the Meteorites. — Prom the fact that me- 

 teorites consist invariably and almost exclusively of nickel and 

 iron, it might, at first, be concluded that the small planetary 

 bodies which are now known to circulate in such numbers in 

 orbits intersected by the orbit of our earth, especially in August 

 and November, consist only of these metals. But the con- 

 clusion would not be legitimate, if it be true, as there is 

 reason to believe, that gravitation is not the only force which causes 

 meteorites to be precipitated on our earth. It is remarkable 



