High Resolution in the Infrared

Abstract

An instrument is described which is capable of giving an experimental resolving power of ten thousand in the near infrared region. With this instrument several of the infrared lines of helium I have been examined and their components resolved. The exceedingly faint lines of the neon I spectrum lying between 1\ensuremath{\mu} and 2\ensuremath{\mu} have been discovered and their wave-lengths measured.