render the reservoirs at such establishments efficacious filters, by some peculiar adaptations in their construction? The reservoir at the Ducal Palace of Venice affords an instance of the kind; for its centre consists of a large circular well, which is formed with a bed of sand surrounding it, so that all the water passes through, and consequently flows in a pellucid state to the fountain, whence the inhabitants obtain it. In those places where the supply of water is usually procured from rivers constantly in motion, the adoption of such a plan would prove highly advantageous, and such sources would generally furnish the means of having a large head-pressure of water to facilitate the attainment of its object. This circumstance may not be unworthy of the consideration of engineers, in the arrangement of any new works, or the improvement of others that have been heretofore constructed.

The exigencies and enjoyments of mankind have frequently occupied the serious attention of philosophical observers, who, after nicely scrutinizing the varied operations of nature, have endeavoured to deduce rational and useful conclusions. One of their statements is remarkable, and probably resulted from a rigid examination and comparison of facts: these have led to the inference that the average quantity of water supplied by rain, in some climates and situations, has a relative proportion to the absolute wants of the inhabitants of a populous city. It would, however, be indiscreet to rely solely upon such a casual source, which might occasionally expose them to much inconvenience, from the time of rain falling, as well as its quantity, being both variable and uncertain. Hence, in many cases, a deficiency might occur, when plenty was most desirable; and the probability of such contingencies, imperatively urge to the adoption of

methods, which may be certainly effective for attaining so important an object, as a plentiful supply of salubrious water to a great population, whatever difference may happen in the state of the seasons.

The site of Lisbon, as well as the ground in its vicinity, consists chiefly of limestone and basalt, which render it necessary to obtain good water, at about three leagues distance, for the beverage, and other uses of the inhabitants. The source consists of several springs that are near to the village of Bellas, and their produce is conveyed to Lisbon by an aqueduct, constructed of a kind of white marble, and finished in 1738. In some parts its course has been excavated through hills; but near to Lisbon it is carried over a deep valley, for a length of 2400 feet, by means of several bold arches, of which the largest has a height of about 250 feet, by a breadth of 115. The arches being pointed have an interesting aspect, particularly when viewed from below, the interior of the spacious vaults being not only majestic in appearance, but reverberating every sound. The water flows through a stone tunnel, or covered arch-way, about eight feet wide, formed in the middle of the structure; and on each side there is a foot-path, with a parapet wall, having a sufficient width for two persons to walk. The aqueduct enters the town, on its northern side, at a place called da Amoreira, where it branches into several others, in order to supply the different fountains, from which the inhabitants are supplied. Persons, denominated gallegos, obtain a subsistence by selling the water, which they procure at the fountains in small barrels, and afterwards cry it through the streets.

Formerly Algiers had neither wells nor fountains, but considerable improvements, in this respect, have been introduced into that once renowned seat of barbarism

and piracy. It is at present supplied with excellent water, from the mountains in its vicinity, by two aqueducts, which have been constructed to convey it to various fountains, erected for the purpose of its distribution amongst the inhabitants.

The city of Valetta, in the island of Malta, derives its supply of water from a source near to Bosquetta; and an aqueduct, consisting of some thousands of arches, conveys it to the inhabitants. The execution of this immense work is said to have been effected, at the private expense of one of the Grand Masters.

The inhabitants of nearly all the capitals, as well as the principal cities and towns on the continent of Europe, and other parts of the world, are, however, supplied with water, either from contiguous rivers, or by wells formed for the purpose. The sale of this necessary article of human subsistence, also furnishes employment, in some countries, to a great number of people, who earn, by such an occupation, a miserable livelihood. Such was formerly the case in many, and, to a certain degree, is still so in some, of the large towns even of this country. But the practice has evidently prevailed from an immemorial period; for "hewers of wood and drawers of water," is a proverbial expression of the highest antiquity, and seems to have been generally employed to designate that painful and toilsome labour, which obtained but trivial remuneration, and was deemed nearly, if not quite, equivalent to positive slavery. How striking the contrast, how inestimably superior, in every point of view, the methods introduced by science and art, to afford the abundant supply of water to London, Edinburgh, and other great cities in Britain!

CHAPTER X.

Methods employed by the ancient Romans to obtain clear water. Magnificent structures of the opulent. Baths of Dioclesian, Antoninus Caracalla, and Titus. Sumptuous baths of private individuals. First aqueduct constructed by Appius Claudius. Roman custom of bathing on different occasions. Gymnastic exercises connected with the baths: temperature of the water various. Use of oils and perfumes. Reflections of Pliny. Number of aqueducts increased by Agrippa. Frontinus appointed to the office of Edile: his meritorious conduct. Large quantity of water supplied to Rome. Cloacæ.

THE multitudes of civilized people congregating in great cities, have not only the same positive wants as the rude inhabitants of the woods and the wilds, but their habits and tastes are also connected with a diversity of conveniences and comforts, requiring a plentiful supply of water. Hence, many practices, introduced during the progress of refinement and luxury, have rendered schemes for readily affording a large quantity, important objects for exercising genius and stimulating industry. Probably a more appropriate and striking illustration of this statement cannot be adduced than that of ancient Rome, where the public and private pleasures or amusements of its inhabitants, or attention to health and cleanliness, led them to construct very stupendous works, to supply abundance of water for their various purposes. Though the ravages of time, and the violence of barbarians, have either injured or destroyed many of their elaborate and magnificent structures, yet the whole of some, and parts of others, still remain to gratify curiosity,

and excite admiration; so that susceptible and cultivated man comtemplates such noble and useful contrivances with the most lively emotions, as extraordinary monuments of human ingenuity and labour. To the philosophical observer they prove fertile sources of instruction, by exhibiting the state of science, and the excellence attained in architecture and several other arts, at the era of their construction, as well as by vividly and forcibly pourtraying the voluptuous propensities, habits, and enjoyments, which formerly prevailed amongst the opulent, ambitious, and haughty residents of "the eternal city."

During that splendid and extraordinary career pursued by the Romans, till they attained the acmé of their glory, the wealthy and powerful amongst them not only acquired a taste for the most luxurious pleasures, but vied with each other in the erection of magnificent edifices, suitable for every purpose conducive to their enjoyment. The diversified productions of genius and skill were eagerly and incessantly sought to augment the number and intensity of their gratifications. Hence, originated the construction of extensive galleries, supported by marble columns and noble arches, covered and embellished with similar materials. The most elegant and transcendant works of art, consisting of statues, paintings, and basso relievos, adorned these superb structures, which sometimes contained the plunder of cities, and even that of whole provinces. Indeed, their historians and orators represent the military commanders, and civil governors, as alike practising the greatest enormities to obtain possession of the master-pieces of Grecian sculptors, painters, and other artists. Even Marcellus, Scipio, and Paulus. Æmilius, although so much eulogized for other achievements, indulged in the most audacious rapacity, by scizing