Speculum metal Sentence Examples

speculum metal
  • Rutherfurd introduced into common use the reflection grating, finding that speculum metal was less trying than glass to the diamond point, upon the permanence of which so much depends.

    0
    0
  • His speculum metal is composed of four atoms of copper (126.4 parts) and one of tin (58.9 parts), a brilliant alloy, which resists tarnish better than any other compound tried.

    0
    0
  • Such speculum metal is exceedingly hard and brittle, takes a fine white polish, and when protected from damp has little liability to tarnish.

    0
    0
  • The best speculum metal and the greatest care are no guarantee of freedom from tarnish, and, if such a mirror is much exposed, as it must be in the hands of an active observer, frequent repolishing will probably be necessary.

    0
    0
  • Glass is lighter, stiffer, less costly and easier to work than speculum metal.

    0
    0
  • In speculum metal there are 2 to 21 parts of copper to 1 of tin.

    0
    0
  • Chiefly owing to the brittleness of this material, Lord Rosse's first larger specula were composed of a number of thin plates of speculum metal (sixteen for a 3-foot mirror) soldered on the back of a strong but light framework made of a peculiar kind of brass (2.75 of copper to 1 of zinc), which has the same expansion as his speculum metal.

    0
    0