Company to sell to those who consume water in manufactories; while, in some cases, it may be so construed as to forbid their sinking new or enlarging old wells to supply themselves. Take the case of a brewer, whose supply is cut off by the immense pumping power of the Company: by the last clause (p. 4) of the Bill, the new Company can only sell to those Companies who sell again and distribute; and except the brewers, &c. &c., be included in that definition as selling water, though in a manufactured state, the new Company have no power to sell to them; but if they be so included, they are prohibited by pp. 5 and 7 from supplying themselves by any new or improved wells. They are thus left at the mercy of the intermediate Companies, to avoid which they have been at enormous expense, and would not be able to obtain spring water at all at a low temperature (for that, after all, is the grand consideration). It is no trifling argument against the scheme, that in case of its partial success, it makes a monopoly of the only existing defence against present or possible misconduct on the part of the existing Companies. While a supply remains in the ground, which, though not adequate to the wants of the whole metropolis, is enough to withdraw on occasion a considerable number of the Company's customers, little need be feared; but when that source, too, is placed in the power of a body, which by the terms of its existence is bound to maintain a good understanding with the other Companies, the public will be left without refuge or power of remedy. This is no hypothetical case: many of the manufacturers of the metropolis have been, or thought they have been, under the necessity of defending themselves by this very measure, of which defence they could not have availed themselves had this Company been previously in exist ence. To all these objections it will, perhaps, be replied, that the Bill subjects the Company to the control of the metropolitan Members of Parliament as a Board, and makes even its exclusive privilege dependent on them. We doubt much the political propriety of this part of the scheme, and certainly cannot expect either that the affairs of the Com pany will be administered without political partiality, or that the interest of the water-companies, for and against, will not be brought to play a prominent part in the election of Members-not much to the improvement of our legislative body. But this objection apart, what is it this Board of metropolitan representatives is empowered to do? Why, besides making regulations on subjects not at all affecting the present view of the case, it may, on proof of abuse of the privilege, or of its having become a public injury or inconvenience, declare the exclusive privilege forfeited. Now for four-fifths of the practical mischiefs of the plan this affords no remedy at all. For, first, it is doubtful whether the stopping of half the works in London, dependent on wells, could be deemed such a public injury as to jus tify the Board in cancelling the privilege; and, next, the Board has no power to revoke permission to work their wells-it can simply permit others to work wells too. What then does a brewer, a distiller, or a manufacturer gain, if, on finding his water fails, he complains of the Company, and succeeds to the utmost? He gets their privilege determined, but some other good neighbour finishes the little that remains of the business by sinking another well. There is then but one supposition, that of an abundant undiminishing supply, on which the project of the Company will not do great and irremediable mischief; and the facts which have come to our knowledge respecting the existing private wells, have firmly convinced us that no such supply exists. The rapid lowering of all wells when severely pumped, the influence of distant wells on each other as they are drawn upon, and the gradual subsidence of the supply to all pumps, as the metropolis and its manufactures have extended, are among other facts utterly irreconcilable with the existence of the inexhaustible supply assumed as the basis of this scheme. But if it be not found, it is idle to suppose that the immense machinery of the Company, being once erected, will not be worked, let the consequence to others be what they may. And to what public purpose is all this expense and hopeless risk? Is there any likelihood that if obtained the water could be delivered to consumers pure as it comes from the earth, after exposure in reservoirs and traversing miles of pipes? And if not, what is gained he tween that supply and the present? We are far from having exhausted the objections both against the scheme and the bill; but we think we have said enough to convince Parliament and the public that their sanction of the Experiment" ought to be deferred till its projectors have devised some means of try ing it less objectionable than those of spending, in the face of such risks, as much money as success alone could justify, and doing more mischief in spite of warning, than any probable success could remedy. And if gentlemen, though men of character, persist in promoting schemes whose fallacy may be proved by facts notorious or easily learned, and propose to execute them in modes which involve an immense outlay, and therefore a great profit to somebody before the confiding subscribers can be undeceived, they must not be surprised if they are suspected of being influenced by motives a little more selfish, than anxiety for either the profit of their supporters or the good of the public. THE LAW OF PATENTS, Sir,-The subject of the law of patents for inventions being brought again under the consideration of the public, by the introduction into the House of Lords, by Lord Brougham, of a bill for amending that law, I beg to send, for the consideration of your readers, the draft of a bill which I prepared some months ago; and I shall be glad of their opinions as to its utility as far as it goes. My object has been to allow the patentee to amend, but only after passing through such an ordeal as few would like to encounter. As to the expense of a patent-what should be the subject of a patent-and other points which have been raised in other bills, I know there exists such diversity of opinion about them, that they would certainly much endanger the carrying through of any proposed measure of which they should form part. I am, Sir, your obedient servant, 15, New Boswell-court, Lincoln's Inn, A Bill intituled an Act to secure the property of inventors in their inventions under letters patent. Whereas it is expedient that the property of inventors in their inventions, for which letters patent have been, or shall be hereafter, granted, should be secured; be it enacted by the King's most excellent Majesty, by and with the advice and consent of the Lords spiritual and temporal, and Commons, in this present Parliament assembled, and by the authority of the same, that no such patent shall be void, although the subject thereof shall have been previously used, if the same shall have been used privately or in an imperfect manner only. And whereas it sometimes happens that omissions or errors are accidentally, or unintentionally, made in the letters patent, or in the specification inrolled in conformity with the provisions thereof, in consequence of which such letters patent are held to be void or voidable; be it enacted, that no letters patent shall be at once wholly void or voidable either on account of want of novelty in the invention or of insufficiency in the description. Provided always, and be it further enacted, that whenever upon the trial of any issue in, or directed by, either of the superior courts of record at Westminster, the validity or sufficiency of a patent or specification shall come in question, and the same shall be found to be invalid, or insufficient, in consequence of such patent, or specification, having been made, or left, or contínued, erroneous, defective, or insufficient in description, the Jury trying such issue shall be directed to find, by their verdict, whether such patent or specification shall or shall not have been so made, or left, or continued, erroneous, defective, or insufficient in description, for the purpose of defrauding the public of the full benefit of the invention, or of deceiving any person; and if the undisturbed verdict of the Jury shall be in the affirmative, then and in such case the patent shall be null and void to all intents and purposes whatsoever: Provided always, nevertheless, that if the verdict of the Jury shall be in the negative, then and in such case it shall be lawful for the Lord High Chancellor or keeper of the great seal, upon petition made to him stating the several facts of the case, and the finding of the Jury, to direct such alteration in the patent and specification, or either of them, and in such manner and form, and at such time, and upon such terms and conditions, as he shall think fit. And for the purpose of preventing fraudulent collusion between the parties to any such issue, be it further enacted, that no such alteration shall be directed, unless his Majesty's Attorney-General, or Solicitor-General, or some harrister named by one of them, shall have been instructed by one, or both, or all, of such parties, and shall, at the expense of one, or both, or all, of such parties, have attended the trial of such issue on the part of his Majesty alone, and shall have certified his satisfaction with the finding of the Jury," and that in his opinion alteration may properly be directed. And be it further enacted, that this Act shall come into force, and take effect, from and after the passing thereof; and that all the provisions therein contained shall apply to all letters patent then unexpired, as well as to all letters patent thereafter to be granted. And be it further enacted, that this Act shall extend to Scotland and Ireland. [Judging of Lord Brougham's bill from the speech with which his Lordship introduced it to the notice of the House of Lords, it is a very crude and ill-digested affair, not at all likely to be passed; and if it were passed, more likely to do harm than good. His Lordship is evidently but very imperfectly acquainted with the actual defects of the law which he has undertaken to amend: he does not know where the shoe pinches, though truth to speak, the whereabouts is no great secret. Neither can we say that our friend Mr. Rosser's proposed bill grapples with the evils of the existing system, in the way that the interests of the public and the interests of inventors alike demand; though so far as it goes it is certainly a much better bill than that of the learned lord. However, we shall be glad to be favoured with the opinions of any of our intelligent correspondents on the subject, and shall ourselves return to it as soon as we can obtain a copy of Lord Brougham's bill.-ED. M. M.] MOTION OF FLUIDS. Sir,-1 am by no means offended, although certainly somewhat surprised, at the comments of J. L. in your last number, upon my description of a singular hydraulic phenomenon. The writer's arguments appear even more singular than the phenomenon to which they refer. J. L. says, p. 92, "it is an established fact, that the jet of water issuing through simple orifices is contracted, in a certain degree, in proportion to the extent of that orifice;" but I beg to observe, that I have been for the last fifteen years in the constant habit of observing jets issuing from apertures of various sizes, urged by dif ferent forces, but I never met with any one instance of perceptible contraction, until the experiment with the flat-topped cylindrical branch-pipe, as described at p. 6. In this statement I am also corroborated by many persons, whose experience in these matters has been far inore extensive than my own. At the same time that this branch pipe was tried, and the remarkable contraction witnessed, a tapering branchpipe of the usual form was also used with a seven-eighths nose-pipe, and (unfortu nately for J. L.'s hypothesis) no contrac tion ensued; the stream of water deli vered, being full seven-eighths of an inch in diameter. To the question of J. L., whether the branch-pipe was held vertically, I reply, certainly not; or the holder, as well as the observers, would have been deluged with water. The branch was held in different positions, at angles of from 20° to 40° from the perpendicular; but change of position did not seem to influence the result. I am not quite sure what J. L. means by the force of gravity, because it is difficult to separate this idea from the force of a column of water of some de terminate height; certain it is, that gravity alone will not produce any contrac tion of the stream, even in the form of vessel described at p. 6. The working of the engine had proceeded far beyond the point of pressure that gravity alone could produce, before the contraction took place; in fact, it was only under great pressure that the phenomenon obtained. It appears to me, that J. L. has been misled, by M. Bossut's "Tables of the Ratios of the theoretical to the real discharges of fluids from circular tubes one inch in diameter, under the pressure of columns, varying from one to fifteen feet high," inserted in the Engineer's pocketbook for the present year. The theoretical to the real discharge, under the pressure of a one-foot column, is said to be as 1 to 0.62133; and under the pressure of a fifteen-feet column, as 1 to 0.61716. This difference is no where attributed to any contraction, which is a gratuitous interpretation of J. L.'s. The difference between the estimated and actual discharge, arises from the varied velocities of different portions of the fluid; the particles of water in contact with the sides of the containing vessel are retarded by friction, and move more slowly than the particles in the centre of the stream, which move with the greatest velocity-perhaps with that which is theoretically due to them. Great, as doubtless is the utility of M. Bossut's tables in all circumstances coinciding with the experiments from which they were obtained, still they are by no means applicable to jets issuing with great velocity. M. Bossut himself states that the results vary much with slightly altered circumstances; but it is evident they must assume an entirely new character, under a force equal to the production of a jet sixty or seventy feet high-a pressure at least ten times greater than any he investigated. I am perfectly convinced that a contraction equal to that which was witnessed in the experiment described at p. 6, was never observed, certainly never recorded before; and it is pretty generally admitted, that this fact is one of the most singular and extraordinary phenomena in the motion of fluids with which we are at present acquainted. I could explain much farther, but I think I have said enough to convince J. L. that he has taken quite an erroneous view of the matter. I remain, yours respectfully, London, May 12, 1835.] SUGGESTION OF A NEW SOURCE OF Sir, I have frequently, during calms at sea, observed the rudder of the ships raised as her stern sinks, and fall again as her stern rises, resembling the motion of a piston in a steam-engine. Now, might not this motive power be turned to some useful account? I am aware of Lord Dundonald's proposal, in No. 583 of your Magazine; but that involves the employment of immense masses of quicksilver. My idea is, that the motion of a ship's rudder, weighing perhaps five or six tons, rising and falling on its hinges, as it does in the swell of the sea, might be applied to propelling purposes; or rather that machinery might be constructed to take advantage of that rising and falling, for the rudder itself could not well be applied to such a purpose. At the same time, I merely throw out the idea with the view that ingenious men may consider of it. I am, Sir, Your obedient servant, JOHN NORTON. U. S. Club, April 28, 1835. MUSCULAR FORCE. i Sir, The case in archery which I stated in your interesting Magazine, p. 306, No. 555, was given in the hope that it would excite some discussion, likely to correct erroneous ideas on the subject of muscular power, and the force of springs. My own views of the case had been previously given, in an early Number of the "Gentleman's Magazine,' for the present year, and therefore I did not require the kind of answer furnished by your correspondent, J. W. (p. 434). According to him, a person holding the fifty-pound bow in his left hand, and drawing the string with his right, exerts a force of a hundred pounds. If so, let me ask him what force each person exerts, when one holds the bow and another draws the string? Again, let a straight stick be provided, capable of supporting, when placed vertically on 66 a deal table," or on the floor, fifty-one pounds, and of such a length as to be put end-wise between the bow and string when drawn; in this case, will it not, without giving way, maintain the bow so bent? I am Sir, A Well-wisher to your publication, A. M. NOTICE OF THE HOT-AIR SYSTEM OF SMELTING IN GREAT BRITAIN. BY M. DUFRESNOY. (Abridgment continued from p. 104.) Derby Iron-Works.-The coal basin of Derby, a prolongation of that of Sheffield, contains many large iron-works; three of them, the Butterly, Codnor Park, and Alpdon works, have adopted the hot-air blast. I visited the first two, under the charge of Mr. Jessop, one of the most intelligent ironmasters in the kingdom. The heating apparatus of all these differ from those I have described, and, in some essential respects, from each other. For this reason I have deemed it proper to describe them in detail, though the results which they give are not so favourable as these obtained at the Calder works. Butterly Iron-Works contain three smelting furnaces. The iron there made is intended for castings, either of first or second runnings. One furnace only was in blast when I visited Derbyshire. The air for the blast was heated by an apparatus at each tuyere, com posed of large pipes, 27 inches diameter in the clear, placed horizontally one over the other, and separated by arched plates. These pipes are connected in pairs, by elbow pipes. The air from the blast-engine enters by the pipe, passes the length of the three pipes successively, before passing into the atmo. sphere. The joints are placed on the outside of the furnace proper; but to prevent the air from being cooled in traversing the elbows, they are cased in brick-work. The elbows connecting the long pipes are in plates, connected by bolts and nuts, passing through lugs or flanges. The pipes are 1 inches thick, and rest upon fire-lumps, placed at proper distances upon the arch plates. This disposition allows the flame to envelope them on all sides. The first pipe is not exposed directly to the action of the fire; it is separated from the grate by an arch of brick, extending the whole length of the furnace, which allows the flame to pass by the flues. The partitions have openings placed at the opposite ends of the furnace, so as to compel the flame to traverse the whole length, without escaping from one story to another. All the arches are of fire-brick, one brick thick. The expenditure of this apparatus is 62 cwt. for To know the whole expense of fuel, that used by the blast engine must be added, for which I have no precise data; but this expense must necessarily diminish in proportion to the increased yield of the furnace. At Butterly, therefore, a saving of onehalf the fuel has been effected by the introduction of the new plan. The quantity of flux remains the same, because the sulphurous nature of the coal requires a large proportion of lime. The blast-engine, which served but two furnaces, now works three; but to obtain this increase, a larger cylinder was put in. Formerly, the cylinder was 70 inches in diameter, and 8 feet stroke, working 13 revolutions; now, the cylinder is 80 inches, the length of stroke, and number of revolutions, remaining the same. The quantity of air expended, which was 2,500 cubic feet per minute, is now reduced to 2,160 feet; but the pressure, 2 lbs. to the inch, has undergone no variation. The opening at the mouth of the tuyere has been reduced from 2 to 3 inches; the iron produced is intended for castings. Codnor Park Works.-This work consists of three furnaces, three refineries, and a suf ficient number of puddling furnaces to work up all the metal. These furnaces have worked for the past year with heated air and crude coal. The substitution of heated air has produced a saving of fuel similar to that stated for Butterly; 2 tons 9 cwt. being now sufficient to obtain 1 ton of metal, which formerly required 5 tons. It should be remarked, that the expense of coal has always been less at Codnor Park than at Butterly, on account of the difference in the quality of iron produced. This difference would be much more sensible, if the same quality of coal was used at both works; but at Codnor Park the soft coal is used, while at the other a variety called cherry-coal is used, which better resists the action of the blast. Consumption for one ton, using Cold Blast. ............ 5 |