Morphology of spiral galaxies. I. General properties.

Red Palomar Sky Survey plates are scanned to characterize a complete sample of 605 spiral galaxies north of declination -33 deg having inclination angle less than 56 deg and blue diameter 2-15 arcmin. The selection of the data and the reduction and parameter-extraction procedures are explained, and the data and the results of statistical analysis are presented in tables and graphs. Findings reported include a low frequency of occurrence for small inclination angles (suggesting distortion of outer structures), similar distributions of central disk brightness for types Sa-Sc but not for types Sd-Sm (where mean values are smaller), fewer late-type galaxies with large exponential-disk scale lengths, no galaxies with both high central brightness and large scale length (indicating a limit on angular momentum in galaxy formation), and a correlation between mean surface brightness and absolute magnitude for later-type galaxies but not for types Sa-Scd.