Page:Popular Science Monthly Volume 5.djvu/710

690 audience, and another will follow on every Friday afternoon during the summer.

One of the largest and most successful aquaria anywhere is that at Brighton, England. It is a private enterprise, and of very recent origin. It was originated by Mr. Edward Birch, an English engineer of note, who organized a stock company with a capital of $400,000. The work of construction was begun in 1869, and the building was formally thrown open to the public in August, 1872. The building stands upon the sea-beach, in front of the Marine Parade, its roof being a little below the level of that promenade. It has a total length of 715 feet, with a width of 100 feet. The interior is divided into two corridors, on either side of which stand the tanks containing the fish. The dominant style of architecture is the Italian, and highly ornate. The roof of the corridors is arched and groined, "constructed of variegated bricks, and supported on columns of Bath stone, polished serpentine marble, and Aberdeen granite. The capital of each column is elaborately carved in some appropriate marine device, while the floor, in correspondence, is laid out in acrostic tiles." The tanks number forty-one. Their fronts are made of plate-glass, one inch thick, divided into sheets three feet wide and six feet high, supported by upright iron mullions. At the eastern end of the west or main corridor is a fernery, with rock-work and cascade. Many of the tanks are also supplied with ornamental rock-work. For the accommodation of visitors there are a restaurant, dining-hall, and reading-room, in the building. The smallest tank measures 11 feet long by 10 broad, and contains about 4,000 gallons of water, while the largest measures 130 feet long, 30 broad, and holds 110,000 gallons. The latter is large enough to accommodate a small whale. At present, however, it contains only a porpoise, a few dog-fish, a ray, and several turtle. Six tanks are devoted to fresh-water animals, the rest to marine. The water of the latter is pumped up from the sea by steam when needed, but is never changed in any of the tanks except when required by turbidity, or any accident, such as the cracking of a front. To secure abundant aeration each tank is supplied with several vulcanite tubes, entering at the top and descending to the bottom. An air-pump, situated at one end of the building, and worked by steam, forces a stream of air into the tank through each tube. The result is, a constant bubbling up of the water. This plan, however, does not seem to be as desirable or efficient as the circulatory system maintained at the Crystal Palace Aquarium. This consists in merely pumping the water by steam up to a higher level, and allowing it to return, by force of gravity, through the tanks to the reservoir beneath. In its course it takes up a greater amount of oxygen than can be otherwise imparted to it, and at the same time acquires great clearness and brilliancy.

The best kind of vessel for a small aquarium is an oblong tank made of slate, with a glass front. Glass may be used instead of slate,