The National Geographic Society and Cornell University have set up a three-year comprehensive program of research on the aurora borealis, as seen in lower latitudes, 40° to 45° north. Parallactic height-measurements are made from four stations. The base-line, Cornell Aurora Observatory, Ithaca, New York (76° 29′ west, 42° 29′ north), to the tower of Colgate Memorial Chapel, Hamilton, New York (75° 33′ west, 42° 49′ north),is equipped with special auroral cameras with lenses of 45-mm focus and aperture F/2. The base-line, Fuertes Observatory, Ithaca, New York (76° 29′ west, 42° 27′ north), to Smith Observatory, Hobart College, Geneva, New York (77° 00′ west, 42° 53′ north), is equipped with auroral cameras loaned by the Auroral Committee of the International Union of Geodesy and Geophysics. Each camera takes six separate photographs on a plate 9 by 12 cm. The plates used are 1-C special, panchromatic, and 1-G special green-sensitive, specially coated by the Eastman Kodak Company. These plates have greater speed and finer grain than any other high-speed plates known to be available. About 500 photographs were taken between September, 1938, and April 24, 1939, of which about 100 pairs are suitable for heightmeasurement. No height-measurements have yet been made from these negatives (see Fig. 1).

+More

auroral cameras

C. W. Gartlein,.Progress-report of the National Geographic Society-Cornell University study of aurora. 20 (3),371-373.

C. W. Gartlein,"Progress-report of the National Geographic Society-Cornell University study of aurora" 20

C. W. Gartlein,"Progress-report of the National Geographic Society-Cornell University study of aurora"