When it comes to gemstones, rarity often directly affects value. And few stones can rival the near-mythical status of ...

THE peculiar phenomena exhibited by quartz in directions slightly inclined to the optic axis were explained by Airy in 1831 on the hypothesis that in any such direction two streams of permanent type ...

THERE is a point in connection with the ordinary expositions of Fresnel's theory of double refraction to which, on account of its frequent occurrence, it is perhaps worth while to direct attention. It ...

Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character, Vol. 80, No. 535 (Dec. 9, 1907), pp. 28-44 (17 pages) ...

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in ...

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in ...