Smithsonian Contributions to Knowledge. Vol. XXXIV. 



Plate XXV. 



CLAVIUS, LOXGOMONTANUS, TYCHO, ETC. PHOTOGRAPHED BY RITCHEY. NO\EiMBEK 21, 

 SEVEN HOURS, THIRTY-TWO MINUTES P. M., CENTRAL STANDARD TIME. 

 SCALE. THREE-FOURTHS METER TO MOON'S DIAMETER. 



I'.ioi. 



