Iceland+spar
51Positive rotation — Positive Pos i*tive, a. [OE. positif, F. positif, L. positivus. See {Position}.] 1. Having a real position, existence, or energy; existing in fact; real; actual; opposed to negative. Positive good. Bacon. [1913 Webster] 2. Derived from an object… …
52Positive sign — Positive Pos i*tive, a. [OE. positif, F. positif, L. positivus. See {Position}.] 1. Having a real position, existence, or energy; existing in fact; real; actual; opposed to negative. Positive good. Bacon. [1913 Webster] 2. Derived from an object… …
53Prism — (pr[i^]z m), n. [L. prisma, Gr. pri sma, fr. pri zein, pri ein, to saw: cf. F. prisme.] 1. (Geom.) A solid whose bases or ends are any similar, equal, and parallel plane figures, and whose sides are parallelograms. [1913 Webster] Note: Prisms of… …
54vitreous electricity — Positive Pos i*tive, a. [OE. positif, F. positif, L. positivus. See {Position}.] 1. Having a real position, existence, or energy; existing in fact; real; actual; opposed to negative. Positive good. Bacon. [1913 Webster] 2. Derived from an object… …
55Ole Rømer — Rømer redirects here. For other uses, see Romer (disambiguation). Ole Rømer Ole Rømer, portrait by Jacob Coning from c. 1700 …
56George Gabriel Stokes — Infobox Scientist box width = 300px name = George Stokes image size = 220px caption = Sir George Gabriel Stokes, 1st Baronet (1819–1903) birth date = birth date|1819|8|13|df=y birth place = Skreen, County Sligo, Ireland death date = death date… …
57List of fictional books — A fictional book is a non existent book created specifically for (i.e. within) a work of fiction. This is not a list of works of fiction (i.e., actual novels, mysteries, etc), but rather imaginary books that do not actually exist.UsesSuch a book… …
58Bashkortostan — This article is about a federal subject of Russia. For the newspaper, see Bashkortostan (newspaper). Republic of Bashkortostan Республика Башкортостан (Russian) Башҡортостан Республикаһы (Bashkir)    …
59Nicol prism — A Nicol prism A Nicol prism is a type of polarizer, an optical device used to produce a polarized beam of light from an unpolarized beam. See polarized light. It was the first type of polarizing prism to be invented, in 1828 by William Nicol… …
60William Nicol — (1770 1851) was a Scottish physicist and geologist who invented the first device for obtaining plane polarized light the Nicol prism in 1828. He was born in 1770 in Humbie (East Lothian), not 1768 as previously thoughtFact|date=February… …
