A three-dimensional equation for deriving the scattering properties per unit volume of interplanetary space is obtained. The equation is related to the zodiacal light intensity observed from a photometer set in some arbirary position relative to the zodiacal light symmetry plane.

A new technique to perform speckle interferometric measurements at J, H, K, L and M wavelengths is described. The time-averaged spatial frequency power spectrum of an image is obtained by scanning it successively over a series of gratings of differing spacing. Some measurements on a 1.5-m telescope are reported which show that diffraction-limited

JHKLM photometry of Nova Cygni 1978 taken over the period 1978 September 20-26 is presented. Evidence for a strong depression in the L band is noted. There is no evidence for an M band emission peak exceeding about 0.1 mag.

An exhaustive description of the visible spectrum of Beta Ori from the Balmer discontinuity to about 9000 A is reported. Equivalent widths and radial-velocity values for the most significant lines in the spectral range studied are presented. Moreover, an automatic data processing technique is described.

By 1980 there will be approximately 100 large optical telescopes in the world with mirror or lens diameters of one meter (39 inches) and larger. This atlas gives information on these telescopes and shows their locations on continent-sized maps. Observatory locations considered suitable for the construction of future large telescopes are also shown.

A simple standard criterion for computer measurement of the equivalent widths of digitized blended spectral lines and for drawing a local continuum as defined by Ardeberg (1975) is outlined. A procedure is developed with which the user need only select the spectral interval enclosing the line blend and the spectral features themselves determine the