of any deposit or accumulation of filth on the newly made part of the river bed; and as any impurities mechanically suspended, will always be nearest the surface, and being thus suspended, will be continually attracted by the shore (and the difference of gravity, and the strength of current being considered), it is evident that the upper or surface part of the filtering bed will always be clean, and in contact with the cleanest and purest water in the river.

And as a further evidence that the bed of the river, under which the filter is made, must be perfectly cleared from deposit, it is well known, that where the current over a filter is stronger than the progress of the water through the filter, there can be no deposit, which would be the case in this instance; and besides, as a further reason that there can be no deposit, which can remain on the upper bed of the filter, the engine which will draw up the water, will only be required to be worked twelve hours per day, and that only during a part of the tide ; and as the water falls in the river, so will the filtered water fall in the reservoir, to find its level, and thereby return upwards through the filter bed; and having been already filtered in its passage down, cannot possibly leave a deposit in the filtering chamber, and must clear away, of necessity, all impurities on the top of the bed, by disturbing the sediment (if any) that might be on the bed of the filter, and which sediment would then be carried away by the current of the river, from over the upper surface of the filtering bed.

It may here be remarked, that the water in the filtering chamber would not be liable to the influence of either the sun or frost, from its being below the action of both, and the water would be constantly fresh and cool from the river, as the filter would be in operation for supply, only while the steam power is at work.

As the water is filtered, and passes into the chamber,

it will be conveyed by the pipe to the well on shore, where it will be completely within reach of pumps worked by steam power, and this communication from the chamber to the well must be made by sinking the well shaft on the shore, while the coffer dam is building, and projecting from the well shaft a horizontal tunnel to the coffer dam, into which an entrance is to be made, at or near the feet of the piles forming that side of the dam next the shore.

An air pipe, not represented in the drawing, may be made to pass through the supply pipe, and up the well, to carry off any air which may get into the upper part of the filter chamber.

When the filter is completed, and in operation, there will not be any obstruction to the Navigation of the river; to all appearance it will be the same as if the filter was not in existence.

II. ON THE EMPLOYMENT OF MACHINERY.

To the Editor of the London Journal of Arts.

SIR,-I again obtrude upon your indulgence, hoping that my purpose may plead sufficient excuse, for as the use and progress of machinery is a subject of such vital importance, both as regards individual advantage and national prosperity, I consider it the duty of every one at all related to, or interested in manufacturing concerns, to stand forward in behalf of such measures as are highly conducive to its well being, and to plead in defence of tried and substantial means, unquestionably beneficial to the commercial interests of his country (none more so than the advancement and perfection of productive power); and

VOL. VII. SECOND SERIES.

it equally behoves those who may be ever so unconnected with business or trade, to refute error-to reconcile prejudice and to endeavour to allay public excitement, which, even when directed to the acquirement of good and valuable ends, is mostly fraught with a mischievous tendency, but lately raised against the possession and enjoyment of an extraordinary benefit would, if persevered in, have been the effective cause of incalculable and irreparable injury. It is still a very favourite idea with many, that machinery is directly detrimental not only to the poor and labouring classes, but also to the general good of the country. These lovers of opposition base their arguments chiefly upon the prevailing distress, without considering that so far from machinery being the producing cause, it is the only remedy (and that from its partial use but an imperfect one), which prevents our sudden dissolution and commercial death. In taking a disinterested view of the subject, we shall find that through this means principally we have been enabled to defray the annual expenses of our debt-that under its flourishing influence, we have greatly increased our capital-that it has chiefly furnished us power and wealth, adequate to support an unrivalled navy-and from the intercourse with foreign nations, necessary to keep up a commercial correspondence-that it has enlarged our views, promoted speculation, strengthened our resources, and added to our importance both at home and abroad. The more immediate cause of our distress proceeds from a very different source to that which the enemies of all improvement or invention would ascribe it; it is from the existence of laws, enacted (if we may judge from the success of their effect) to impoverish and starve the industrious part of the community; it is from hastily curtailing our currency to a state of total inadequacy, yet continuing those oppressive restrictions which maintain

provisions at a price inaccessible to the labouring poor; it is from closing our markets upon the graiu and produce of other countries-naturally causing them to return the compliment upon us-greatly and materially to our loss. It would not be more ungrateful and absurd to deprive the generous horse of its legs, whilst employed in the cultivation of our land, through whose valuable assistance in preparing the soil, we expect to reap an abundant harvest, and then barbarously to turn upon it with the goad and lash for its inactivity and incapability of motion, than it now is, under our existing depression, to raise an unavailing cry against the important benefits derivable from the use of machinery. If I might presume modestly to venture an opinion, so far from machinery producing or increasing our distress, that distress arises from the illiberal restrictions which curb its progress, limit its use, and cramp the whole energies of the nation.

It has been ably proved, that population only increases in equal proportion as the means of subsistence increase; when we consider that the numerical strength of our country is more than doubled within the last twenty years, and that the number of acres within the kingdom cannot possibly have undergone a like increase, this inquiry naturally suggests itself-from whence then have we derived the means to subsist so great an addition of numbers? I will answer by our commerce, by the aid of our machinery, which alone has enabled us to extend our commerce to the necessary degree, by the rapidity and perfection of our inventions, which have given us a triumphant victory over aspiring rivals. The accumulation of capital, the reward of our successful endeavours, serviceably employed in the improvement of our land, has by rendering it doubly productive, furnished occupation for many, food for all. It may be urged if machinery had not existed,

the increase in population would never have taken place; but the productive powers of the soil must also have remained unimproved for want of capital so to be invested, which capital has been accumulated solely by its creative means, with the immense burden of debt and taxes thrown thus wholly upon the shoulders of the land, how could we have stemmed the overwhelming torrent of distress, which must have inevitably ensued. By our manufactures, by our machinery (the nerves, the life, the very vitals of our commerce) we have hitherto in a great measure relieved it from these sinking and oppressive weights. Allowing that the land, unimproved, were capable of producing considerably more than the nation as it before existed required, or could possibly consume, where could a market have been found to give sales and returns with adequate profit, to keep a yearly deteriorating soil in repair, had it not been for our machinery to call forth a consuming population into existence, and continued inventions, and extended improvements to furnish that population with means and wealth to buy? Of what use is it, let me ask, to raise corn, if money or some necessary equivalent cannot be furnished in exchange; to give it away could, in the end enrich neither the donor or receiver, but ruin both, and cause universal stagnation. Is it then fair, is it politic, is it just to turn round upon that source of our prosperity and wealth-our machinery: that very friend which has furnished every necessary equivalent, and to pray for its abolition, denounce its long enjoyed services, and with the savage spirit of oppression, to trample its favours undeservedly and scornfully in the dust?

It is doubted and denied by the gentleman who has styled himself an inquirer into commercial distress, and headed his laboured production by practice opposed to