TANTALUS, the This, in natural histo ry, a genus of birds of the order Grafix, Ceneric character : bill long ; thick at the base, inenrvated ; face naked, and sometimes all the head ; tongue broad and short ; nostrils linear and oval ; four toes, connected by a membrane at the base. There are nineteen species, of which we shall notice the following: T. loculator, the wood ibis, is of the size of a goose, and the length of three feet, and is found in Carolina, and in many coun tries of South America, haunting, parti cularly, those low tracts which are inun dated during summer. These birds subsist on reptiles and fish, have little sa gacity, and are often seen in cypress trees of extraordinary height, with their heavy bills reposing on their breasts. They are in use for the table, though far from be ing excellent.
T. ruber, or the scarlet ibis, is found in America, and the neighbouring islands. Its plumage is of a most ardent scarlet, and it is one of the most beautiful birds of the genus. It subsists on insects, and the ova of fishes, for which, on the ebbing of the tide, it frequents the shores. It perches in trees, but lays its eggs on the ground. The old birds and the young keep in distinct flocks. They do not at tain the full lustre and glow of plumage till their third year ; and in sickness and confinement lose almost all their brilliancy.
T. ibis, or the Egyptian ibis, is more than three feet long, and as large as a stork. On the retreating of the Nile, it is
found in Lower Egypt in great numbers, subsisting on insects and frogs. It perches on palm trees, and sleeps in an erect atti tude, its tail touching its legs. It is sup posed by some naturalists to be the ibis of the ancients, and is known to destroy and devour serpents. Others suppose it to be the ox-bird described by Shaw. For the blackheaded ibis, see Ayes, Plate XIV. fig. 2.
TANTALUS's cup, in hydraulics, a si phon, so adapted to a cup, that the short leg being in the cup, the long leg may go down through the bottom of it.
The betided siphon is called Tantalus's cup, from the resemblance of the experi ment made with an image in the glass, re presenting Tantalus in the fable, fixed up in the middle of the cup, with a siphon concealed in his body, beginning in the bottom of his feet, and ascending to the upper part ()ibis breast ; there it makes a turn, and descends through the, other leg, on which he stands; and from thence down through the bottom of the cup; where it runs out, and causes the water to subside in the cup ; as soon as it rises to the height of the siphon, or to the chin of the image, the water will begin to run through the siphon concealed in the fi gure, till the cup is emptied in the man ner explained under siphon, and repre sented more distinctly in the article Hy.