THE AQUARIUM MANY tourists who have gone to Naples within recent years will recall their visit to the aquarium there among their most pleasant experiences. It is, indeed, a place worth seeing. Any Neapolitan will direct you to the beautiful white building which it occupies in the public park close by the water's side. The park itself, statue-guarded and palm-studded, is one of the show-places of the city; and the aquarium building, standing isolated near its centre, is worthy of its surroundings. As seen from the bay, it gleams white amid the half-tropical foliage, with the circling rampart of hills, flanked by Vesuvius itself, for background. And near at hand the picturesque cactus growth scrambling over the walls gives precisely the necessary finish to the otherwise rather severe type of the architecture. The ensemble prepares one to be pleased with whatever the structure may have to show within. It prepares one also, though in quite another way, for a surprise; for when one has crossed the threshold and narrow vestibule, while the gleam of the outside brightness still glows before his eyes, he is plunged 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 moving 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 presence, unless a stream of water, with its attendant bubbles, 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.