700,000 MILES OF SUNSPOTS

Extending for 700,000 miles across the face of the sun, a string of spots that astronomers have recently been observing shows unusual solar activity. They are shown in our cover illustration, a photograph made Friday, November 29, at the Yerkes Observatory by Charles D. Higgs. The photograph was made with the 40-inch telescope, the largest in the world with a lens. The spots are in several groups, three of which could be seen with the unaided eye when properly protected with smoked glass or exposed photographic film. The largest single spot was 40,000 miles in diameter, with an "umbra," the dark inner portion, about 20,000 miles across. Several spheres the size of the Earth, 8,000 miles in diameter, could be dropped into this spot. This large spot was on the sun’s center line, as seen from the Earth, Saturday, November 30.

FINDS COMET ON PHOTO

Discovery of a new comet, not in the sky, but on a 10-day-old photographic plate that he was filing, was the recent experience of E.R. Carpenter, of the Seward Observatory of the University of Arizona. The photograph was made of the sky in the constellation of Aries, the ram, on November 2.

At the time the plate was exposed, the comet was not noticed. After Mr. Carpenter found its image on the plate, a further search was made for it in the sky, but the glare of the moon prevented its being seen. When discovered, it was very faint, of the 16^th magnitude, and was moving to the southeast. However, it had a short tail, which is rather unusual for so faint a comet.

If two more observations are made of it, astronomers will be able to calculate its path.

LINDBERGH DISCOVERS CLIFF-DWELLING

In their flight over the home land of the prehistoric Pueblos, Col. and Mrs. Charles A. Lindbergh this summer discovered and visited ruins invisible from the ground and therefore probably never before examined by white explorers. Details of this airplane survey in the Southwest have just been announced by the Carnegie Institution of Washington, with which Col. Lindbergh has cooperated in his efforts to show the value of the airplane to American archæology.

It was while circling the ruins in the Canyon de Chelly that the fliers noted a number of small ruins in the side of the high cliffs. The plane was landed for the night on a flat place on the mesa near by, and next day the aviators climbed the cliffs and examined the ruins, which could not be seen or reached from the depths of the canyon below.