FOUNT

(Fr. for.ds.) The quantity of types of any particular sort in a printing ollice, whether it be gnat or small. Thus a small fount may consist of titty or one hundred pounds weight, eusuuiUng the usual proportion of the various letters of the alphabet; and n large fount of thirty or forty you sand pounds weight, or more. FOUNTALV (Lat. Ions.) By this term is designated any natural or artificial apparatus by means of which water springs up. in natural fountains the ascensional effort is producedbytlie bjrdnstBlfc pie-sure of the water itself; in nrK find fountains it is produced either by the same pn by that of compre ed air, or sometimes by machinery. The theory of natural fountains is extremely simple, and depends on the well-known property of fluids — lhal, when enclosed in tubes or ve els communicating with one another, lhe fluid rises to the same level in all of them; and that i;> pre ure on the side's of the tube at any point is pro] to the height of the vertical column above that point. Sup pose a b and c d to be two pipes communicating with each other, and that water is poured into • at a; it will KSOSnd i iiually in both tubes, though they may lie of very different rises, and stand at lhe same level a c. Let us now suppose the tube c d to he cut away at d, «j and let the line /' d be horizontal; then lhe pre ure at (/ being the same as at h, the water will spring from d with a velocity X — 2y/ g A, >l— where g is lhe accelerating force of gravity (equal to 32 feet in a second of time), and h Is the aliunde of the column a b. [See Hydrodynamics.) The water, therefore, If it suffered no resistance from lhe air, or other impediment, would spring up from d to c. Now it is precisely on this principle that all natural fountains an explained. The rain which falls from the atmosphere is absorbed in three different ways. One part of it collects in rills on the surface of the ground; these unite in stream! or rivulets, which flowing into one another form rivers, and thus it is conveyed to the ocean. A second part is taken up in giving humidity to the soil, from which it is returned to the atmosphere by evaporation. A third portion descends into the earth, through soils of a spongy or porous nature, or through crevices and interstices in the strata, until it meets, frequently at a very considerable depth, with strata through which it cannot penetrate, and is then collected in subterraneous reservoirs. When confined in this manner it is subject to the pre ure of the water which lills the channels through which it lias descended; and when this pleasure i sufficient to overcome the resistance of the superincumbent ma of earth, the water breaks the artificial strata, and gushes forth in a spring. But if the strength of the superincumbent materials exceed the hydrostatic pre ure, the water H ill remain stored up as it were in the subterraneous reservoir. Now if the ground above such a reservoir, or any channel communicating with it, be perforated, the water, having free acce to the opening, will rise in it till it attains the level of the highest part of the channels from which it is supplied. If this level is above the surface of the ground, the water will have a tendency to rise; and when the ascensional force is considerable, it may by proper means be formed into a fountain. That subterraneous reservoirs formed in this manner exist in great abundance, and at great depths under the surface, we have sufficient evidence in the facility with which water may be obtained in almost all countries from Artesian Well*. [s. 489]