HEATING AND VENTILATION. Of the many questions that merit attention and study in connection with the Turkish bath, all sink into insignificance by the side of that of the _heating_ and the _nature of the heat_ supplied in the sudatory chambers. Other things being equal, it is, after all, the _heating_ that distinguishes one bath from another on the score of excellence. The heating of the "bath" is the Alpha and Omega of the whole matter. There are two ways in which heat may be applied to the body--by direct radiation, as from the sun or an open fire; and by convection, as through a volume of air. The ancient Roman bathers, with floors below them which rested upon _pilæ_, or little pillars of brick or tile, around which the flames and hot gases from the furnace played, and surrounded by heated, hollow walls, evidently submitted themselves to the action of a heat that must have been of a purely radiating character. So, also, in a less perfect manner, the Turks, who employ flues running beneath the floors, and the Moors, who adopt stoves visible to the bathers. Theoretically, radiant heat in a bath is vastly superior to that which is transmitted to the body through the medium of the air. Its virtues have been extolled by David Urquhart and other eminent authorities on the bath. "There is a difference," says Mr. Urquhart, "between radiating and transmitted caloric.... I cannot pretend to treat of this great secret of nature; to work out this problem a Liebig is required. This I can say, that such heat is more endurable than common heat. There is a liveliness about it which transmitted heat lacks. You are conscious of an electrical action. It is to transmitted heat what champagne is to flat beer.... Let us drop, if you please, the word 'bath': it is 'heat.' Let us away with that absurdity 'hot-air': it is the application of heat to the human frame." Elsewhere this writer has pointed out that the terms _thermæ_, _sèjac_, and _hammâm_--the names given to the bath by the Romans, Moors, and Orientals proper--mean _heat_, and not "hot-air" or "hot-air bath."