DIPLEIDOSCOPE n.
An instrument for determining the time of apparent noon. It consists of two mirrors and a plane glass disposed in the form of a prism, so that, by the reflections of the sun's rays from their surfaces, two images are presented to the eye, moving in opposite directions, and coinciding at the instant the sun's center is…
DIRT n.
In placer mining, earth, gravel, etc., before washing. Dirt bed (Geom.), a layer of clayey earth forming a stratum in a geological formation. Dirt beds are common among the coal measures. -- Dirt eating. (a) The use of certain kinds of clay for food, existing among some tribes of Indians; geophagism. Humboldt. (b) (Me…
DUST n.
- called also smut. -- Gold dust, fine particles of gold, such as are obtained in placer mining; -- often used as money, being transferred by weight. -- In dust and ashes. See under Ashes. -- To bite the dust. See under Bite, v. t. -- To raise, or kick up, dust, to make a commotion. [Colloq.] -- To throw dust in on…