various directions suggested by the re- be provided at the front so as to permit photographs to on all sides, and large trees grow near, so that it is cent work of the Yerkes Observatory, including the be taken simultaneously through as many different lines difficult to get a photograph of the… … Reservoir of Bordj-Djedid Restored. of hydrogen, iron, and other elements; further appli- the celostat mirror having a diameter of 30 inches. Prof. EK E. Barnard, professor of astronomy of the cation of the methods of photographing sections of A second plane mirror 24 inches in diameter reflects…
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