Smithsonian Contributions to Knowledge, Vol. XXXIV. 



Plate XXII. 



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MARE TKAXC2UILITATIS AND SURROUNDINGS. PHOTOGRAPHED BY RITCHEY. AUGL ST 3, liiOl, 



TWO HOURS THIRTY MINUTES A. M., CENTRAL STANDARD TIME. EXPOSURE, 



THREE-FOURTHS SECOND. SCALE, THREE-FOURTHS 



METER TO MOON'S DIAMETER. 



