It will be long ere we call to rival this thriving city but capital, skill, and enterprise, connected with the powerful aid of the Shaws water, will accomplish more, and in less time, than many imagine. This work is going on slowly, but surely and has accomplished a great deal in the short period that has elapsed since its completion. From it the town and public works can have all supply of water; the pipes being laid along our streets and lanes to both extremities of the town, as well as through the policy. Before proceeding further, it may be as well to give some account of a work which has been the admiration of some of the most scientific men of the age.

The deficiency of water had been long a subject of complaint in Greenock; and, in dry seasons, it had to be carted for the supply of the inhabitants from a considerable distance. Many attempts were made with the desire of remedying this; but until the establishment of the Shaws Water Co., nothing of importance was effected. Mr. Rennie made it survey, and increased the Supply a little, by erecting a small reservoir near the town but it was usually exhausted by two or three weeks of dry weather. About forty years ago, the late Mr. Watt, accompanied by the late Mr. George Robertson, also walked over the whole neighbouring grounds, and gave it as his opinion, that nothing could be done but by small reservoirs, such as that afterwards made by Mr. Rennie. It appeared to Mr. Thom of Rothsay, however, that by turning the source of the Shaws water and other streams in the hills behind, and constructing reservoirs and aqueducts, the town might be plentifully supplied with water; but the attempt was by many pronounced impracticable, without raising it over the hills by force of steam. In 1824 he prepared a report, in which he stated it not only practicable to procure a Supply sufficient for the use of the inhabitants, but also to impel machinery, to an extent at least equal to what is impelled by steam in and about Glasgow. In consequence of this, a company was immediately formed, and incorporated by act of pailiament, under the name of "The Shaws Water Cornpany" with a capital of £31,000 Sterling.

For the information of those at a distance, as also of others interested, we subjoin a plan of the whole. The description which now follows, showing the present state of the works, and their capability of further extension, is from a pamphlet entitled Account of Shaws Water, &c.

The compensation reservoir, the auxiliary reservoir No. 3, the main aqueduct, (something more than six miles in length,) and the eastern line of mill leads, were finished early in April 1827, and on the 16th day of that month the water, from the great reservoir, was brought along the aqueduct, and down this eastern line to the Baker's Mill; which has ever since been supplied at the rate of twelve hundred cubic feet per minute for twelve hours in the day, agreeably to the regulations. Other three mill sites have also been feued on this line, and the necessary erections are in a considerable state of forwardness.

"The embankment of the great reservoir, which is 60 feet high from the bottom of the rivulet, is now finished.

This reservoir contains two hundred and eighty-four millions, six hundred and seventy-eight thousand, five hundred and fifty (284,678,550) cubic feet of water; and covers two hundred and ninety-four and three-fourths imperial acres of land.

The compensation reservoir contains fourteen millions, four hundred and sixty-five thousand, eight hundred and ninety-eight (11,465,89S) cubic feet of water, and covers about forty imperial acres. Its embankment is 23 feet high from the bottom of the rivulet.

The auxiliary reservoir, No. 3, contains four millions, six hundred and fifty-two thousand, seven hundred and seventy-five (4,652,775) cubic feet of water ; and covers about ten imperial acres.

" The other auxiliary reservoirs, Nos. 1, 2, 4, 5, and 6, are now about to be formed, and will contain something more than six millions cubic feet of water.

Thus, the reservoirs already formed contain three hundred and three mil. lions, seven hundred and ninety-seven thousand, two hundred and twenty- three (303,797,223) cubic feet ; and when the other five auxiliary reservoirs are finished, the whole will contain above three hundred and ten millions (310,000,000) cubic feet of water.

The whole annual supply, originally estimated, was six hundred millions (600,000,000) cubic feet. The Company have stipulated to supply the east line.

procure a supply sufficient for the use of the inhabitants, but also to impel machinery, to an extent at least equal to what is impelled by steam in and about Glasgow. In consequence of this, a company was immediately formed, and incorporated by act of parliament, under the name of ''The Shaw's Water Company," with a capital of £31,000 Sterling.

For the information of those at a distance, as also of others interested, we subjoin a plan of the whole. The description winch now follows, showing the present state of the works, and their capability of further extension, is from a pamphlet entitled "Account of Shaws Water," &c.

The compensation reservoir, the auxiliary reservoir No. 3, the main aqueduct, (something more than six miles in length,) and the eastern line of mill leads, were finished early in April 1627, and on the 1601 day of that month the water, from the great reservoir, was brought along the aqueduct, and down this eastern line to the Baker's Mill; which has ever since been supplied at the rate of twelve hundred cubic feet per minute for twelve hours in the day, agreeably to the regulations. Other three mill sites have also been fetied on this line, and the necessary erections are in a considerable state of forwardness.

The embankment of the great reservoir, which is 60 feet high from the bottom of the rivulet, is now finished.

"This reservoir contains two hundred and eighty-four millions, six hundred and seventy-eight thousand, five hundred and fifty (2S4,678,550) cubic feet of water ; and covers two hundred and ninety-four and three-fourths imperial acres of land.

"The compensation reservoir contains fourteen millions, four hundred and sixty-five thousand, eight hundred and ninety-eight (14,405,898) cubic feet of water, and covers about forty imperial acres. Its embankment is 23 feet high from the bottom of the rivulet.

"The auxiliary reservoir, No. 3, contains four millions, six hundred and fifty-two thousand, seven hundred and seventy-five (.1,652,775) cubic feet of water ; and covers about ten imperial acres.

The other auxiliary reservoirs, Nos. 1, 2, 4, 5, and 6, are now about to be formed, and will contain something more than six millions cubic feet of water.

Thus, the reservoirs already formed contain three hundred and three millions, seven hundred and ninety-seven thousand, two hundred and twenty- three (303,797,223) cubic feet ; and when the other five auxiliary reservoirs are finished, the whole will contain above three hundred and ten millions (310,000,000) cubic feet of water.

The whole annual supply, originally estimated, was six hundred millions (600,000,000) CSIIJiC feet. The Company have stipulated to supply the east line

of mills with twelve hundred (1200) cubic feet per minute, for three hundred and ten days (of twelve hours each) in the year; and it is intended to give an equal supply to the west line; This will amount to five hundred and thirty- five millions, six hundred and eighty thousand (535,680,000) Cubic feet annually. Taking the population of Greenock at 25,000, and allowing for each individual two cubic feet a-day, this will require eighteen millions, two hundred and fifty thousand cubic feet annually ; which leaves, of the original six hundred millions, forty-five millions, seventy thousand (15,070,000) cubic feet annually, for the public works and other purposes.

"The available drainage into the various reservoirs now formed, is above seven hundred millions of cubic feet annually; and it will be observed that the reservoirs are capable of containing a full supply for the whole consumpt for more than six months; so that not only the surplus waters of one wet season may be retained for supplying the dry season of the same year, but the surplus of several wet years stored up to supply a drought of several years duration, should such ever occur—Any doubt of a full supply of water, at all times and in all seasons, to an extent much beyond what has been stipulated for by the company, is altogether out of the question.

The water for the supply of the inhabitants, sugar works, and others requiring pure water, is collected into reservoirs, set apart for that purpose, and as little as may be of moss water admitted into them. A separate aqueduct has also been made to carry this water to the filters, just above the town, where a basin has also been made, large enough to contain something more than a day's supply of the filtered water. This aqueduct, which is fully fifteen inches square, is perfectly water-tight ; being formed with stone, nicely joined and cemented; and costs something less than one-third the price of a cast iron pipe of equal capacity. Wherever the pressure is not great, such a conduit is preferable to an iron pipe; as the water, by passing over stone, is rather improved than injured, which is not the case with iron. In this aqueduct, (which is deep enough in the earth to avoid the frost of winter and the heat of summer,) cess pools are formed for the deposit of sediment; it being desirable that the water should be as pure as the nature of things will permit before it enters the filters.

Three filters are now formed: each is fifty feet long, twelve wide, and eight deep. The water is made to percolate through them, either upwards or downwards, at pleasure. When it percolates downwards, and the supply of filtered water becomes sensibly less—which, after some time, must happen to every filter, by the lodgement of sediment—then, by shutting one sluice, and opening another, the water is made to pass upwards with considerable force, and, carrying the sediment along with it, falls into a waste drain made for that purpose. When the lodged sediment is thus removed, and the water begins to run clear, the direction of the sluices is again changed, and the filter operates as before.

"If the water usually percolates upwards, then, as before, when the quantity of filtered water falls short, one sluice is shut and another opened, and the water, passing downwards with considerable force, carries the sediment along wills it Into the waste drain, in either case the sediment is removed, and the filter again at work in less than an hour. This much sought for desideratum in filters has, therefore, at last been found; and Greenock is now supplied with abundance of pure water, at the very low rate of Gd. the pound of rental, being only half the price paid in Edinburgh and Glasgow.

"The water is carried, by an aqueduct, from the river and reservoirs, to a populous sea-port town, with a redundant unemployed population, where roads, harbours, piers, and every thing requisite for the most extensive trade and manufacture, are already formed. Besides, by thus forming artificial waterfalls on advantageous grounds, every inch of fall, from the river or reservoir to the sea, is thus rendered available. In the present case a fall of 512 feet has been made available, of which not more than 20 was formerly occupied, or thought capable of being usefully employed. But, besides the immense advantage thus gained by increasing the fall, a still greater advantage is obtained from the greatly increased, and perfectly uniform, supply of water.

"It has already been stated, that the reservoirs have been made so capacious as to contain a full supply, for the whole works, for six months; which enables the surplus of wet years to be retained to supply the deficiency of those that are dry and it will be seen, by the following description, that these reservoirs, aqueducts, basins, and self-acting sluices, turn to account every drop of water that flows from the whole drainage, during even the greatest floods; whereas, by former plans, a very large portion of these floods was allowed to run waste. fully to the sea."

The various self-acting sluices, which are nine in number, have been all contrived or invented by the ingenious Mr. Thom, Civil Engineer, Rothsay. All we can do is merely to notice, by naming the various sluices, and referring for farther particulars to the pamphlet already alluded to. Those who have had an opportunity of seeing them in operation, must admire the simplicity and ease with which this immense body of water is regulated. Many may still remember the devastation which was caused by the bursting of the dam above Cartsdyke, on the 15th March, 1815, when the stream, in its resistless course, Carried every thing before it, till it almost flooded the whole of Cartsdyke. Here this cannot occur; for the body of water is so kept in check, through the various self-acting sluices, that during the stormiest night, and should the ''rains fall as it were their last," in silence and loneliness they would act on, with that safety and precision, which gives security to the district where the various embankments have been made.

"THE LEVER SLUICE.—This apparatus, when placed on a reservoir that supplies any canal, mill, or other work with water, (where the aqueduct between the reservoir and such work is on a level,) will always open of its own accord, and let down the quantity of water wanted by such work, and no more; so that it not only supersedes a water-man, but also saves a great deal of water.

"THE WASTER SLUICE.—This sluice, when placed upon the embankment of any river, canal, reservoir, or collection of water, prevents the water within the embankment from rising above the height we choose to assign to it; for whenever it rises to that height, the sluice opens and asses the extra water and whenever that extra water is passed, it Shuts again, so that, while it saves the banks at all times from overflow, it never wastes any water we wish to retain.

THE DOUBLE-VALVE SLUICE.—This apparatus answers the same purpose as the lever sluice, but is more applicable in cases where the reservoir is deep, and the embankment consequently large. it also acts as a water-sluice, by opening and passing the extra water whenever it passes in the reservoir the least above the height assigned, and thereby supersedes a bye-lead.

In making hydraulic experiments, it will also be found of considerable importance; as, by keeping the surface of the water in the cistern, from which we draw water for the experiments, always exactly at the same height, it not only saves intricate calculations, but renders the result, upon the whole, more correct.

THE SINGLE VALVE SLUICE.—The construction of this apparatus is. in some respects, similar to the double valve sluice; but its application is to situations where the reservoir is on high grounds, and where the water has to pass down a declivity before it is applied as a power to the mills.

THE CHAIN SLUICE.—This apparatus answers exactly the same purpose as the last; only the construction is different.

THE DOUBLE WEATHER SLUICES.—This apparatus is so far similar to the last described ; but it has a double operation, the sluices first opening, one after another, as the streams increase, until they reach a given height ; and then shutting, one after another, as they continue to rise above that height. Again, when the streams begin to fall, the sluices open, one after another, until they (the streams) fall to a certain point; and then again shut, one after another, as they continue to fall below that point the same continuous rise in the streams first opening, and then shutting, all these sluices in succession ; and, in like manner, the same continuous fall first opening, and then shutting, them in succession.

 THE SINGLE WEATHER SLUICE.—One of the purposes to which this apparatus is applicable, is to regulate the supply of water between a reservoir and mill, or other works, where thc former is at a great distance from and high above, the latter ; where several streams fall into the aqueduct between them; and where the adoption of apparatus might be considered too expensive. But it may also be applied to several other useful purposes, as will readily occur to such as may have occasion to adopt it."

Before leaving the subject, we have only to remark, that to Mr. Thom Greenock is under a debt of gratitude. This enterprising, and, we may say, highly talented individual, has changed as it were the face of nature ; and where a comparatively barren hill reared its head, life, animation, and cultivation are to be seen. For ages the stream sought a different channel, and poured itself into the Clyde near Ardgowan. In the short period of two years its course was entirely changed a little lake formed between the hills; and the various streams which fonts this "Caspian" are brought along the brow of the hill, till they reach Everton, and from thence run off as circumstances may require. All this has been done by a gentleman at once modest and intelligent; but to allude to his talents, we have only to point to the Shaws Water, which will snake his name remembered while the stream itself continues to exist.

In conclusion, we copy from the ''Greenock Advertiser," of the 17th April, 1827, the following interesting account of the opening of the Shaws Water Aqueduct, which tookplace on previous day:-

"The 16th of April, 1827, will long remain a memorable day in the annals of Greenock. Rapid as was its advance from the obscurity of a fishing village to the consideration which belongs to the first sea-port in Scotland, we trust it is destined from this day to exhibit a still more rapid progress as a manufacturing town, for which it has acquired facilities it did not before possess—and, we may add, which no place in the United Kingdom now possesses in the same eminent degree.

"To form an immense artificial lake, in the bosom of the neighbouring alpine regions, and lead its liquid treasure along the mountain summits, at an elevation of more than 500 feet above the level of the sea, till, in the immediate vicinity of the town, it should be made to pour down a resistless torrent, in successive falls, for the impelling of machinery to a vast extent—this, in a few words, was the magnificent conception of Mr.Thom; and never, probably, did the first trial of so novel and extensive an undertaking demonstrate its capability and entire adaptation to its purpose, or excite such unalloyed and universal gratification.

"By the activity of Mr. James Thom, the engineer of the Shaws Water Company, all the preparations were completed, to admit of the water flowing from the great reservoir the whole length of the aqueduct, a distance of 6 miles; and yesterday, precisely at a quarter to twelve, the sluices were raised by our Chief Magistrate, William Leitch, Esq., who immediately thereafter entered a boat prepared for the purpose, gaily decorated with flags, and was floated along on the first tide of the stream in its new and artificial channel. The spectacle of it vessel skirting the mountain's brow, and tracking the sinuosities of the alpine chain at so great an elevation, seemed the realization of a dream of the wildest fancy; and the course of the boat was followed by crowds of delighted spectators. It arrived at Everton, in the vicinity of the town, exactly at a quarter to three, where it was received with cheers and a salute of cannons The water was then allowed to flow into the regulating basin for three quartets of an hour. It is at this point that the stream takes its descending course; and a sufficiency of water having been poured into the basin, at half-past three the sluice was opened by Sir Michael Shaw Stewart, and the torrent bounded down each successive fall, and rolled along the alternate levels, with fearful activity. It was at this juncture that the scene became one of the most interesting and animated description. The spectators, who amounted to several thousands, but who had previously been scattered irregularly over a considerable extent of the aqueduct line, now became more condensed, and moved onwards as if in procession, following the march of the stream. In the appearance of the aqueduct a complete change had now taken place: what, a few minutes before, was a dry and unmeaning channel, exhibited now an impetuous torrent; by turns a cascade sending up clouds of spray, and a swift rolling current seeking its unquiet course towards the Clyde, whose ample waters lay far beneath. Arriving at length at one of the lowest falls, on which the new Flour Mills belonging to the Society of Bakers have been erected, the Shaws Water no longer disported itself idly and iii vain. The dizzying wheel was set in motion, with the fine machinery of the mills, and added new life to the scene. A discharge of cannon announced this event also. The mills and granary are on an extensive scale, and the former are driven by a water power equal to 28 horses. The machinery, which has been constructed by Mr. John Wood, engineer, is remarkably fine, and by competent judges is pronounced inferior to nothing of the kind in Scotland. At half- past four, the Shaws Water, which for ages had discharged itself into the Clyde at Innerkip, now terminated its easterly course in the river above this town.

"In conclusion, we cannot help remarking, as a most singular circumstance, that the birth-place of Watt should have become the theatre for exhibiting time earliest practical demonstrations, on an extensive scale, of a great mechanical power, rivalling the utility of his own; and been the means of adding another name to the bright record of ingenious men, who have proved at once time benefactors of their country and of mankind."