The rotation of constant deviation prisms

✍ Scribed by W.E. Forsythe

• Book ID: 104121531
• Publisher: Elsevier Science
• Year: 1917
• Tongue: English
• Weight: 107 KB
• Volume: 183
• Category: Article
• ISSN: 0016-0032
• DOI: 10.1016/s0016-0032(17)90720-3

✦ Synopsis

Three tungsten mirrors were used, one polished Coolidge X-ray target, and two polished flattened wires mounted in evacuated soft glass bulbs, with terminals for heating electrically. All mirrors gave concordant values at the points at which they were compared. The spectrometer was provided with a fluorite prisna and a bolometer. The length of air-path, the number of silvered reflecting surfaces, and the angles of reflection from these, surfaces were kept constant in all measurements. Slit-width corrections were applied. The temperatures were measured by \Vorthing and Forsythe on an optical pyrometer.

The results obtained are summarized in the following table: Wave-length Absolute reflectivity in. at room temperature Per cent. increase in reflectivity in going from room temperature to in per cent. I377°K. I628°K. I853°K. 2o56° K. 0.67 5 t -}-6.0 +7.4 +8.7 -}-9.8 0.8o 55 +8.2 1.27 70 o.o o.o o.o o.o