speculum metal

American  

noun

1. any of several bronze alloys with a high tin content, often containing other materials, as silver, brass, lead, zinc, or arsenic, used for making mirrors and reflectors.

---

speculum metal British  

noun

1. a white hard brittle corrosion-resistant alloy of copper (55–70 per cent) and tin with smaller amounts of other metals. It takes a high polish and is used for mirrors, lamp reflectors, ornamental ware, etc

---

Etymology

Origin of speculum metal

First recorded in 1790–1800

---

Example Sentences

See Examples For:

speculum metal

It is employed pure for numerous purposes, and is also mixed with other metals to form bell metal, speculum metal, for optical purposes, and German silver.

From The Mines and its Wonders by William Henry Giles Kingston

For making speculum metal plates either plane or concave we use polishers so hard that they scratch the metal all over the surface with fine microscopic scratches.

From On Laboratory Arts by Richard Threlfall

Mr. Maudslay was interested in the idea I suggested; and he requested me to show him what I knew of the art of compounding the alloy called speculum metal.

From James Nasmyth: Engineer; an autobiography by Samuel Smiles

The above process may be employed for speculum metal, or pitch may be used.

From On Laboratory Arts by Richard Threlfall

Thus all risk of contractile tension, which is so dangerously eminent and inherent in the case of sand-mould castings, made of so exceedingly brittle an alloy as that of speculum metal, is entirely avoided.

From James Nasmyth: Engineer; an autobiography by Samuel Smiles

Random Word

Spin the wheel and learn a new word!

---