Ocean Gardens. The History of the Marine Aquarium / and the best methods now adopted for its establishment and preservation.

by Henry Noel Humphreys

To remedy this state of things, the evil effects of which soon became apparent, artificial aeration was resorted to, by means of another vessel, which kept up a continuous supply of dripping fresh water. But even this assistance did not enable the crowded colony to exist more than ten days. In the first place, there were many predatory species, which destroyed their associates; these kinds must, therefore, be excluded from an Aquarium, or kept in a separate tank. But, after all, the impossibility of providing a sufficient supply of oxygen was evidently the great and principal cause of failure. The Univalves and smaller Crustacea disappeared first, a disagreeable smell giving intimation that decay was going on, the creatures that had perished having, many of them, died in concealment, under the stones, weeds, &c., at the bottom of the Aquarium. The first signs of unpleasant effluvia rising from the tank must, therefore, be carefully attended to; and, in such cases, the Aquarium ought to be immediately searched for the cause; which, when discovered, should be immediately removed.

Plate XI.
A DESIGN FOR A PLAINLY-MOUNTED AQUARIUM.

Mr. Gosse having taken out the whole of the specimens, dead and alive, and carefully cleansed the tank, a much smaller number was put in, which, being well selected, and having sufficient space, throve abundantly well; and the ingenious experimentalist was at last amply rewarded for all his persevering exertions. This result benefited others as well as himself, for a general taste suddenly arose for this kind of pursuit, among all who read the various works which soon appeared on the subject; and, to gratify the new taste, a host of dealers in Aquaria have sprung up, who are driving a brisk and profitable trade.

The first experiments of Mr. Gosse sufficiently point out the kind of cautions to be observed in the formation of a marine Aquarium. The vessel itself may be either quite plain in its frame-work, as shown in [Plate XI.], or made more or less ornamental, to assimilate, if necessary, with surrounding objects or furniture. The rustic style of frame, designed in [Plate XII.], has been found to accord well with the general character of the Aquarium itself, and it produces an agreeable contrast with the usual forms of the furniture of our ordinary sitting-rooms.

Plate XII.
A DESIGN FOR AN AQUARIUM MOUNTED IN HANDSOME RUSTIC-WORK.

Those made by the dealers are generally formed with slate floors and backs, and zinc columns and mountings; the smallest and most simple, about fifteen inches long by ten inches broad, costing from a guinea to twenty-five shillings, and those of the proportion of two feet by one foot six costing from two pounds ten to three pounds. A small syphon will be useful, in order to remove a portion of the water, if required, without disturbance; and also a syringe, in order to aerate the water when necessary, if a second reservoir of fresh-water, in a suitable position, should not be convenient. A miniature landing-net is also useful for the removal of decaying matter, or occasionally the living specimens when any change may be required.

A layer of sand and pebbles, about three inches deep, placed upon the slate flooring, is the first step towards arranging the interior of the tank. Upon this beginning, removing the sand and stones in places to procure a firm basis, the rock-work may be built; which should be picturesque and fanciful in character, as partially suggested in the two Plates, leaving miniature archways and caves for the shelter of such creatures as shun the light, either constantly or occasionally. Such a disposition of the rock imparts, at the same time, many pleasing effects to the pictorial composition. These matters are not, however, much attended to by dealers, whose arrangements of the Aquaria they offer for sale are generally tasteless enough. But that is perhaps all the better, as it entails upon the amateur the necessity of providing his own taste, which is at all times both a useful and pleasant effort of mind, and which, moreover, leaves, after each period of exertion, a permanent trace of an increased refinement which influences the whole character.

In the distribution of the rocks, I would always allow at least one point to project above the water, in order to afford the opportunity to those animals whose instincts lead them to seek occasional exposure to the air, the means of gratifying it by that contrivance. I have thought, indeed, of constructing a kind of double Aquarium, and perfecting a contrivance by means of which a large portion of water should flow gradually from one tank to the other at fixed periods, in imitation of the ebb and flow of the tide. Many interesting phenomena would be exhibited in this manner, such as the closing of the Actiniæ as the water receded, and their expansion as it covered them on its return. This alternation, too, might be found highly advantageous to the health and development of the animals whose natural habitat lies between high and low water-mark, and whose constitution is therefore framed to require entire or partial exposure to the air at certain intervals of time. I also prefer, as preserving a similar set of analogies, a sloping bottom, similar to that of the coast. For instance, if the slate back of the Aquarium be placed next the light, which is its proper position, as the light ought to penetrate the water entirely through its upper or horizontal surface, then I would fill the side next the slate back nearly to the top with pieces of rock, gradually reducing their height, till, at the other side, they should hardly rise above the floor of sand and pebbles, leaving, at last, a flat portion of the pebbly or sandy bottom quite level.