A HISTORY OF SCIENCE 



suddenly into what seems at first glimpse a cavern of 

 Egyptian darkness, and the contrast is nothing less 

 than startling. To add to the effect, one sees all about 

 him, near the walls of the cavern, weird forms of mov- 

 ing creatures, which seem to be floating about lazily 

 in the air, in grottos which glow with a dim light or 

 sparkle with varied colors. One is really looking 

 through glass walls into tanks of water filled with 

 marine life ; but both glass and water are so transparent 

 that it is difficult at first glimpse to realize their pres- 

 ence, unless a stream of water, with its attendant bub- 

 bles, is playing into the tanks. And even then the 

 effect is most elusive; for the surface of the water, 

 which you are looking up to from below, mirrors the 

 contents of the tanks so perfectly that it is difficult to 

 tell where the reality ends and the image begins, were 

 it not that the duplicated creatures move about with 

 their backs downward in a scene all topsy-turvy. The 

 effect is most fantastic. 



More than that, it is most beautiful as well. You 

 are, in effect, at the bottom of the ocean or rather, at 

 the bottom of many oceans in one. No light comes to 

 you except through the grottos about you grottos 

 haunted by weird forms of the deep, from graceful to 

 grotesque, from almost colorless to gaudy-hued. To 

 your dilated pupils the light itself has the weird glow 

 of unreality. It is all like the wonders of the Arabian 

 Nights made tangible or like a strange spectacular 

 dream. If one were in a great diving-bell at the 

 bottom of the veritable ocean he could hardly feel 

 more detached from the ordinary aerial world of 

 fact. 



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