Knowledge. 



Fia. 1. — Large Thunder-Stonu Cumulus, pbotographed on 1898, August, 23d. Ih 2()m. 



i"io. 2. — Light CiiTO-Cumulus in the L'pper Kegions, with Stratus in the Foreground. 1S97, September, 16d. 4h. 



PHOTOGRAPHS OF CLOUDS. 



