i86 Natural History Bulletin. 



violently that it broke loose and came near doing serious 

 damafje before we again had it under control. Below could 

 be heard the smashing of crockery and glass-ware. Investi- 

 gation showed that very little damage had been done, although 

 we feared the loss of a considerable portion of the jars and 

 dishes which were stored in racks. 



On Wednesday. July 5th. the wind was at last in our favor, 

 and the schooner was able to hold her course across the 

 Bahama Banks. The clear light green of the water on the 

 Banks extending to the horizon on every side, forms a marine 

 view which is almost unique in its coloring. Again we 

 noticed the rich purple effects in the clouds which were so 

 conspicuous when we crossed the Banks the first time. Dr. 

 L. W. Andrews, of the State University of Iowa, suggests 

 that this effect is to be ascribed to the fact that the sensitive- 

 ness of the optic nerve to the green color becomes exhausted 

 by the constant contemplation of the vivid green water, and 

 that purple, the complement of green, appears in place of the 

 blue of the sky. If this were true, it would seem that pro- 

 longed contemplation of green trees and grass would also 

 make the skv appear purple. The actinic power, however, 

 of the green reflections from the water is shown by the 

 fact that such water appears almost \\'hite in a photograph. 

 Stirrup Key Light was sighted in the afternoon, and we once 

 more anchored on the eastern edge of the Banks. 



The next day was spent in beating against a head-wind, 

 the west side of Abaco being made about noon, after which a 

 long tack to the southward occupied the rest of the day until 

 we sighted the lights of Nassau, N. P.. when we came about 

 on the other tack for the remainder of the night. Many of 

 the partv would have been glad to visit the city of Nassau, 

 which is the metropolis of the British West Indies, but our 

 time was getting short, and we were not on a pleasure excur- 

 sion. The comparative idleness of the last two or three days 

 had made the young men so frisky that more than the usual 

 amount of skylarking was indulged in that night, including an 

 impromptu concert, that was not greatly appreciated by those 

 who desired to sleep. 



