It is one of the marvels of the earth's history, that hot springs, or thermal springs, bubble upwards to the light, not only on Mount Ida, the source of the Scamander, but in countless other places and countries on the world's surface. These hot springs would appear to have invited man to their use by their pleasant aspect and by their warmth; and their enjoyment to have suggested the possibility of contriving artificially a similar luxury nearer to his threshold. The word Hamâm, which is equivalent to thermal springs, is not unfrequently met with in the East as the name of a town or village in or near to which hot springs are found. Hamâm Ali, in the neighbourhood of ancient Nineveh, is an example of this kind. "The thermal spring is covered by a building, only commodious for half-savage people, yet the place is much frequented by persons of the better classes both from Baghdad and Mósul."[2] Captain Kennedy, in his "Travels in Algeria and Tunis," tells us of the hot springs of Hamâm Meskhoutin, which rise to the surface at a temperature of 203° of Fahrenheit, only 9° short of boiling, and are so abundant as to burst forth through any opening made accidentally in the ground. "The thermal waters, in flowing over the bank of the rivulet, have formed a calcareous deposit of great beauty, resembling a cascade of the purest white marble, tinged here and there with various shades of green and orange." [2] F. W. Ainsworth: "Journey to Kalah Sherghat and Al Hadhr in 1840" (Transactions of the Geographical Society). In Italy, near the town of Pozzuoli, are some natural thermal springs--the ancient Posidianæ, now called the Baths of Nero, of which the temperature of the water is 185°, while that of the vapour which rises from it is 122°. The spring is situated in a rocky cavern at the end of a long passage formed by a fissure in the rock, and in this way constitutes a natural bathing house. In Germany, among others, are the thermal springs of Borcette, with a temperature of 171°; Carlsbad, in Bohemia, 165°; Wiesbaden, Ems, and Schlangenbad, in Nassau; Baden-Baden; Aix-la-Chapelle; Wildbad; and Ischl. In Iceland are the far-famed Geysers; in the Southern Ocean the hot springs of Amsterdam Island; and many more are dispersed over the Continent of America; while in England there are the thermal springs of Bath, Bristol, Buxton, and Matlock. The _heated rock_ and the _vaporization of water_ would seem to have originated the primitive idea of a hot-air and hot-vapour bath; and this idea we find carried out simultaneously in various parts of the world and amongst the rudest nations. Mr. Gent, in his "History of Virginia," describes the hot-vapour bath as employed by the American Indians.