Spectrum analysis in its application to terrestrial substances, and the physical constitution of the heavenly bodies / familiarly explained by H. Schellen ; translated from the second enlarged and revised German edition by Jane and Caroline Lassell ; edited with notes by William Huggins ; with numerous woodcuts and coloured plates, and Ångström's and Kirchhoff's maps.

  • Heinrich Schellen
Date:
1872
Catalogue details

Licence: Public Domain Mark

Credit: Spectrum analysis in its application to terrestrial substances, and the physical constitution of the heavenly bodies / familiarly explained by H. Schellen ; translated from the second enlarged and revised German edition by Jane and Caroline Lassell ; edited with notes by William Huggins ; with numerous woodcuts and coloured plates, and Ångström's and Kirchhoff's maps. Source: Wellcome Collection.

    50/748 (page 20)
    still high, and stands now at 20s. per ounce.* It may be assumed that the ordinary magnesium wire burns about one grain and a half in a minute, in value about a halfpenny, and evolves a light which in intensity is equal to seventy-four Stearine candles, of which five go to the pound. From these expe- rimental data it may easily be calculated that the unit of light in the combustion of magnesium does not cost much more than its equivalent in Stearine candles. For the magnesium light to be of practical use, Fig. 4. Grant and Solomon’s Magnesium Lamp. the combustion must be under control, and the light so arranged that its concentrated rays can be * [The price in Hopkin and Williams’s (5, New Cavendish Street, W.), catalogue is 12s. per ounce for magnesium in powder for burning.]