The theory of optical instruments has been studied for practically the whole period of modern science, from the Renaissance to the present day. In its earliest form it consisted of simple applications of the laws of reflection and refraction to geometrically simple systems. The analytical theory of the aberrations of axially symmetrical syste, s, on the other hand, has been in existance for a little more than a century. If one reflects that for the most part this comprises only the consequences of the application of Snell's law and elementary coordinate geometry to the very simple geometrical configuration of spherical surfaces with their centres in a straight line, it is remarkable that even here important work both continues and remains to be done.

A resonance lamp is the first sealed, microwave-operated lamp to successfully emit resonance radiation of helium and neon. The lamp produces stable, high-spectral-purity radiation in the far ultraviolet, it has proved adaptable to experimental applications such as studies of the reactions of excited molecules and ions.

Interferometric methods may be used to easily generate zone plates with many of the same properties of conical and hyperbolic lenses. These surfaces would be extremely difficult to fabricate out of glass. Experimental procedures for the production of such hologram lenses using only a collection of slits, spherical lenses, and cylindrical lenses are given. Various imaging systems are described where a given distortion of input transparency coordinates are desired at an image plane of an optical processor. A radar application using one such system is given.

The Earth's atmosphere interferes with the operation of both radio and optical astro nomical telescopes. Conversely, the moon with its large mass and no atmosphere offers many advantages to the astronomer compared to Earth-based or Earth-orbital operations. This paper presents mission and vehicle concepts which utilize the LASSO vehicle system to place two unmanned Lunar Modules (LM) in orbit for subsequent landings on the lunar surface of radio and optical telescope payloads, investigated here is the feasibility of employing standard S-IC and S-11 stages and the modified S-IVB/IU (LASSO) to place 74,210 pounds of payload into a lunar orbit.

Using an equation which has been derived for the variation of apparent star magnitude with star angular altitude, observer station height, star spectral radiance, sensor spectral sensitivity, assumed theoretical values for Rayleigh (pure air) scattering, typical clear sky Mie (large particle) scattering, and Ozone absorption for 18°C temperatures, calculations have been performed for various sensor and star types. A typical result obtained using this method to calculate the total magnitude extinction for an Ao star observed at the Zenith by a 7 sensor at a station height of 1130 ft. is 0.31 magnitude, which compares to the result obtained experimentally by R. H. Hardie at Dyer Observatory, of 0.25 ± 0.02 magnitude. Other similar results are presented.

Beer's law - the absorption- of a solution is generally proportional to the concentration of the solute. c = concentration of solution. b = absorption coefficient for unit concentration.