In this paper data are presented on the ultra-violet reflecting power of various metals-beryllium, chromium, cobalt, nickel, silver, speculum, stellite, and stainless steel. For chromium and beryllium the observations extend into the infra-red. The observations show that contrary to the general experience with other metals, beryllium has a high reflectivity at 250 mn in the ultra-violet, followed by an appreciably lower reflectivity with a minimum at about 400 m/* in the visible spectrum.

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... um has a higher reflectivity than nickel in the ultra-violet and is, therefore, the more efficient as a reflector of ultra-violet radiation. The reflectivity of chromium is conspicuous for its relatively high maximum (70 per cent) at 425 m/* followed by a wide flat minimum which extends from about 600 my. in the orange to wave lengths beyond 2,000 m/z in the infra-red.