424 Chronicles of Science. [July, 



the decarbonizing or converting process, the object of which is to 

 economize the consumption of fuel, and reduce the cost of the 

 metals. 



There is also an invention whereby very superior iron and steel 

 are said to be obtained by smelting titanic iron ore, Ilmenite, in a 

 blast furnace, without the addition of any other metalliferous body ; 

 the alloy of iron thus obtained possesses a large percentage of car- 

 bon. Various methods are adopted to carry out this process. The 

 inventor is Mr. T. S. Webb, of the Norton Iron "Works. 



11. PHYSICS. 



Light. — Spectrum analysis has been applied by Vogelsang and 

 Geissler to the difficult question of determining the chemical nature 

 of the fluid found enclosed, in minute quantity, in the cavities of 

 certain quartz-crystals. Fragments of quartz were placed in a 

 small retort, which was connected with an air-pump and exhausted ; 

 then, by the application of heat, the quartz decrepitated, and the 

 evolved vapour was examined in a Greissler-tube. The presence of 

 carbonic acid was thus abundantly proved, and this was confirmed 

 by the turbidity which it produced in lime-water. 



A great improvement in the spectroscope has been made by 

 Mr. Browning, who calls his instrument the automatic spectroscope. 

 It is furnished with a battery of six equilateral prisms of dense 

 flint glass ; all the prisms are joined together like a chain by their 

 respective comers, the bases being in this manner linked together. 

 This chain of prisms is then bent round so as to form a circle with 

 the apices outwards ; the centre of the base of each prism is attached 

 to a radial rod. All these rods pass through a common centre. 

 The prism nearest the collimator, i. e. the first prism of the train, 

 is a fixture. The movement of the other prisms is then in the pro- 

 portion of 1, 2, 3, 4, and 5, the last or 6th prism moving five times 

 the amount of the second. All these motions are communicated by 

 the revolution of the micrometer screw, which is used for measuring 

 the position of the lines in the spectrum ; and the amount of motion 

 of each, and of the telescope, is so arranged that the prisms are 

 automatically adjusted to the minimum angle of deviation for the 

 ray under examination. It is easy to test the efficiency of the 

 instrument in this respect. On taking the lens out of the eye-piece 

 of the telescope, the whole field of view is found to be filled with 

 the light of the colour of that portion of the spectrum which the 

 observer wishes to examine; while in a spectroscope of the usual 

 construction, at the extreme ends of the spectrum, just where the 

 light is most required, only a lens -shaped fine of light would be 



