THE TECHNOLOGIST. [June 1, 1865. 



4yZ ON MAGNESIUM. 



finally overcame. Now, by machinery of his contrivance, the metal is 

 pressed into wire of various thickness, and a spectator might wonder, as 

 the silver threads stream forth, how that which now seems so easy 

 should have cost such pains. Mr. Mather improved on the wire by 

 flattening it into ribbons, in which form, as a larger surface is exposed 

 to the air, combustion takes place more completely. Mr. Mather 

 likewise made the first lamp for burning magnesium. In it the end 

 of the wire or ribbon was presented to the flame of a spirit-lamp to 

 ensure perfect combustion. As the wire burnt, it was paid out by 

 hand from a reel, and propelled between rollers through a tube, which 

 conducted it to the flame. A concave reflector diffused the light 

 forwards and afforded shade to the eyes of the operator. 



To few could the introduction of the new metal to commerce yield 

 such lively satisfaction as Professor Roscoe, whose hint had been, as it 

 were, the spark which set Mr. Sonstadt's energy afire. It was Dr. 

 Roscoe's lot, moreover, to introduce magnesium to the scientific public. 

 In doing so, he was fortunate in having the assistance of Mr. Brothers, 

 of Manchester, who in the spring of 1864 was the first to take a 

 photograph by the magnesium light. At the Royal Institution in May 

 last year, Professor Roscoe delivered a lecture on light, and among his 

 illustrative experiments, burned some magnesium, and calling forth 

 Professor Faraday from the audience, had him photographed on the spot 

 by Mr. Brothers, and the negative being inserted in the magic lantern a 

 gigantic likeness of the venerable savan was projected on the screen. 

 The same experiment was repeated, with Sir Charles Lyell for a subject, 

 in the Bath Theatre, when Professor Roscoe lectured on light to one of 

 the evening assemblies of the British Association. 



To photographers the magnesium light will prove an inestimable 

 advantage. Smoke, fog, and night need no longer interfere with their 

 operations. A busy man, who cannot afford to lose a forenoon in order 

 to catch the sunshine, may have his likeness taken in the quiet and 

 leisure of an evening at home. Photographs under such circumstances 

 are much more likely to possess that ease and naturalness, which are so 

 difficult to attain under the ordinary conditions of out-of-door costume, 

 an ascent to a house-top by a tedious flight of stairs, and a pose in the 

 glare of a glass-house amid theatrical furniture. As a Quarterly 

 Reviewer observes — 



" The new magnesium light promises to dispense with the necessity 

 of a glass studio with all its discomfort for the sitter, and all the 

 temptation to meretricious decoration which it appears to hold out to 

 the photographer. The metal magnesium, the oxide and carbonate of 

 which is a familiar medicine, is itself rare. It will burn like a candle,* 

 and it emits a light peculiar for its w r onderful richness in chemical 



* No ; not quite like a candle. Magnesium wire should be held downwards, 

 say at an angle of 45° in burning. No more than a paper spill or a wood match 

 will magnesium burn with certainty if the lighted end be held upright. 



