The last patent which has been obtained, is again by Mr. Hancock, in conjunction with Messrs. Macintosh. It is for an improvement in air-tight cushions and beds. Few of our readers need be told that these articles have been of the impervious double texture to a great extent. They have afforded relief to invalids, by whom they have been generally used; and much has been done to increase their utility in particular cases, by making them, in each case, of a shape fitted to relieve the peculiar infirmity. Still, however, they had one fault-a fault, by the way, common to all air-tight beds or cushions, of what. ever material-when pressed with the weight of the body, they felt comparatively hard and solid; and this feeling of solidity increased with the time that the patient remained on them. This arises from the circumstance, that the enclosed air resists compression with greater force than is consistent with the ease of the patient; and the covering or bag (as the double texture is popularly called) of Macintosh, is too inextensible to allow relief by the only other mode-a change of its capacity. To remedy this serious defect, the cover or bag is gathered into deep creases, folds, or puckers, by thin straps of caoutchouc attached to its inner surface in the process of making: the cover itself is thus made elastic, and adapts itself not only by change of shape, but by change of capacity, to any partial pressure: a feeling of ease and softness is thus imparted to it which the invalid well knows how to prize. Dr. Arnott's beautiful contrivance, the hydrostatic bed, does much, and in a similar way, to alleviate the sufferings of protracted disease; but, on many occasions, it may be found inconvenient or inapplicable, and departs, perhaps, too widely from common domestic usage, to be employed extensively in private houses. Mr. Hancock's adds another to the existing means of relief, and that of a kind which readily falls in with old habits and arrangements. It is said that to invalids the improved beds have been found invaluable.

In a late number we noticed the application of caoutchouc to Mr. Cow's boats. We understand that some gentleman in the neighbourhood of Liverpool strenuously urges the use of lifeboats of this material.

It is found to be a much better material than leather for the hose used in breweries, distilleries, &c. We have heard, that, in the brewery of Messrs. Barclay and Co., not less than 2,000 feet of it, of a large size, have been used for some time. For attaching tenders to locomotive engines, it succeeds well; the heat in this case being too great for any other flexible material.

Diving dresses are now fabricated of Indian-rubber cloth: such were used in the late submarine explorations; the long flexible tubes by which air is supplied to the diver are made of linen, saturated with caoutchouc varnish, and covered and lined with sheet rubber. Shoes and galoshes are made in great quantities of the last-named article; many shoemakers having become exceedingly expert in the management of it, and producing shoes of every variety of strength and fashion: from such as are capable of bearing the rough usage of the sportsman to those fitted for the lady's promenade.

The history of the caoutchouc manufacture leaves no doubt as to where the credit of rendering this singular and valuable substance available to personal and domestic comfort ought to remain; and, if public legal justice could always follow the line of actual justice, there can be as little doubt that the pending trial would confirm the legal rights of Messrs. Macintosh and Hancock. It is not for us to guess by what shuffle of law, or quirk of dexterity, substantial justice may be defeated, if it be defeated; but we shall watch the proceedings with interest, for we look for much curious information, as well as for singular illustrations of the present miserable state of the law of patents.

TAIT'S AND HUTCHISON'S GASO-
METERS.

Sir, Mr. Hutchison or Mr. "Clovis," or by whatever other name this "ingenious engineer" chooses to go by, may write on, and writhe and flounder, like a newlyharpooned whale, but I can assure him, that, should he write till doomsday, he can never succeed in persuading any man, of the most moderate understanding, that the gasometer he has taken out a patent for, is not a literal copy,

in all its essential parts, of my "Improved Gasometer," as publicly described, June, 1824. If Hutchison, in fact, had not been perfectly conscious of this, why did he, after giving notice of action last autumn, to the City of London Gas Company, in Dorset-street, respecting two gasometers, which they had just erected on the same plan, decline going into Court? The reason is abundantly obvious. He knew, to a certainty, that his pretensions would have been scouted in any court of law in the kingdom.

I have openly advanced my claim to the invention of this gasometer; and I have substantiated my claim by clear and distinct evidence. What, on the contrary, has "the PATENTEE (!) done?" He has met my demand, and the proofs of it, by a vague and malicious calumny, having no foundation whatever in truth, and for which we have only his bare (and not very impartial) assertion, unsupported by the slightest tittle of evidence, even as to time, circumstance, or place. Is this a way to support a patent right? I allude particularly to the following paragraph, which, is, in fact, the burthen of his song throughout all the other paragraphs of his letter, dressed up in all variety of shapes. "I know also" (he says) that, though he" (Tait)" succeeded in getting a trial made, he suffered the pain of witnessing its complete failure."

Now, if he chooses, I will give him an opportunity of adducing his authority for this, as I have no other alternative left me, under the circumstances of the case, than to tell him-which I do most distinctly-that it is a wilful and deliberate misrepresentation! There is not even the shadow of truth in the above most impudent assertion.

Such base and totally unfounded aspersions on my character as a professional man, are not to be tolerated with impunity; and I must say that a little more deference and respect would not have been unbecoming on his part towards a man whose inventions he had found it convenient not only to copy, but also to take out a patent for!

He is a little more specific, however, in the following paragraph:-"I see, by a document now before me (he says), in Mr. Tait's hand-writing, that HIS gasometer had been tried at Leeds, previous to his public announcement in

June, 1824." He then goes on to argue

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that, as no apparatus of this description is now employed there, corroborative proofs are therefore afforded, not only of TAIT'S GASOMETER being discarded, but that four years ago Stephen Hutchison's invention was unknown." We shall waive the grammar and the logic here, and deal only with the spirit of this paragraph; which, to do it justice, is circumstantial. I have him then tangibly at last.

In June, 1824, as I stated in my former letter, an account of my improved gaso meter was published. About four or five months afterwards, in my way through Leeds, I called, as is usual with us, to look at the gas-works. On seeing Mr. Hurst, the engineer, he asked me if 1 was the person who had published an account of a telescope gasometer; and being answered in the affirmative, told me that he had one in the yard, which had been at work for some years. He showed it to me; and very honestly pointed out its defect, in regard to its inadequate pressure, at an early hour. The fact was, that, although his gasometer was, in every other respect, similar to my own, it differed in one very material point. It was suspended from the centre, by means of a bridge, in the old way. Mr. Hurst had never published any account of his gasometer; and it was, therefore, by no means surprising that I had never heard of it before. After having seen it, however, I made it a point of honour, while recommending my own gasometer, to mention at the same time that which had been previously erected by Mr. Hurst at Leeds. The "document" referred to, therefore, may very possibly be some such communication from me. I have no opportunity of knowing whether Mr. Hurst's gasometer is still working at Leeds or not. I can only say, that it had been at work for some years when I saw it, and had no other fault than what I have just mentioned, which, by suspending it, after my method (as Hutchison has very properly done), would have been easily remedied. But the hydraulic joint of Hurst's gasometer was perfect in every respect so that Mr. Hutchison has, unfortunately for him, no loop-hole to get out at there. It was constructed, as any man of common sense would have constructed it, who was not constrained (by

a contrivance, in order to curtail the columns.) to have the uppermost gasometer the largest. By referring to the paragraph which I have just quoted, it will be seen that he states the gasometer at Leeds to have been MY gasometer. From the "document before him, in my hand-writing," however, he knew, as well as I did, that the gasometer at Leeds was not mine, but Hurst's!

W. TAIT.

THE NEW SAFETY CAB.

We extract the following clear and sensible exposition of the advantages of this new vehicle (the invention of Mr. Hansom, the architect of the Birmingham Town-hall, confessedly one of the finest architectural productions of modern times), from the prospectus of a company which has been formed for promoting its introduction into the me-tropolis:

"The very peculiar construction of this carriage secures advantages that men of science and of practical experience have long wished for, but which have never before been obtained. Instead of an axle going through from side to side of the carriage, Mr. Hansom uses a framework, so contrived, that, while fully able to sustain any shock to which it may be exposed, and admitting the use of wheels of any diameter, it allows the body to be placed at any distance, however small, from the ground. By this contrivance, three most important objects are attained: namely―

:

"1st. Absolute safety for the body is placed so low, and the framework so arranged, as to render it impossible that the carriage should be upset in any direction whatever; nor can a kicking, a rearing, or a stumbling horse place the passengers in danger.

"2d. Great relief to the horse in ресиliar situations: for the centre of gravity of the load being placed below the centre of the wheels, the injurious pressure on the horse, in ascending and descending hills with a 2-wheel carriage of the common construction, is avoided; for in descending, the pressure on his back is entirely removed; while in ascending, a small and advantageous addition is made to it.

"3d. Considerable reduction of draught

in all circumstances: for wheels of larger diameter than usual may be employed, not only without prejudice to the other advantages of the invention, but in promotion of them; and it is on all hands agreed, that very great saving of draught might be effected by the use of large wheels, but for the hitherto supposed impossibility of reconciling them with the other necessary properties and conveniences of a carriage.

*

"The inconvenience and danger of the present cabs have been long, loudly, and justly complained of. The new cab is perfectly and obviously safe, and ef fectually protects passengers from injury by a vicious or stumbling horse; it affords ingress and egress as safe and easy as those of a sedan-chair, and is smoother of motion than many of the best carriages of other kinds; it also combines the shelter and comfort of a close carriage, with the lightness of an open one, and the speed of the best of the present cabs, at the cost of perhaps one-third less labour to the horse, and with the entire avoidance of the injurious effect of common 2-wheel carriages on hilly roads.

*

"In ascents and descents, any moderate degree of safety to the passenger, or of pressure on the horse, has been, hitherto, attainable only by the use of four wheels. Where four are used, they cannot be large: much power is thus lost-to say nothing of the additional friction- and two horses are needed. Absolute safety, and greater comfort to the passengers, and much greater ease to the animal, are now secured by two wheels, and those large ones. The additional horse is thus dispensed with, and posting may be done by one horse, on terms and with a convenience and rapidity yet unaccomplished. The conveyance of mails and dispatches may be done by 2-horse carriages, with the like, or even greater, benefit.

"A carriage has recently been built, and is ready for public inspection and trial, which exemplifies the plan, and fully justifies the preceding observations. It has been subjected to severe trials, both intentionally and by accident; and, by coming out of them without the slightest failure, has proved that

its framework may be safely relied on in any emergency."

GAS LIGHTING PROJECTS.

Mr. Matthews, the author of the "History of Gas Lighting," and "Compendium of the Principles and Practice of Gas Lighting," two works of which we have repeatedly had occasion to speak in terms of high commendation, has lately put forth a pamphlet under the above title, which though the "projects" of which it treats are rather of the "parish class, contains not a few of much general importance. We regard Mr. Matthews as a first-rate authority in all gas inatters, not only because of long and familiar acquaintance with them, but because of the perfect honesty of purpose which characterizes every thing that issues from his pen. In a prefatory introduction to his present pamphlet, he states, that “he never possessed the slightest pecuniary interest in any gas establishment, and that his strictures have been directed by public considerations alone." Although not sorry to see such a declaration, we must say for ourselves that it was quite unnecessary. Nothing but public considera.. tions alone could have dictated the broad, liberal, and in our humble judgment, most just view of the claims of the existing Gas Companies, which is presented by the following extracts :

"Enormous was the cost to the early companies of erecting buildings, constructing apparatus, and burying pipes in the streets, for the purpose of diffusing over this vast metropolis the brilliant but economical light of gas. Nearly all the really valuable improvements in its operations have been effected at their expense; and from the commencement of their career, have not they lighted the public streets either at a positive loss, or for little or no profit? Though in this instance, as well as in various others, conferring an important and extensive benefit upon the community, has the remuneration for the capital and exertions ever much exceeded the common interest of money y? Often it has not even amounted to that, and yet they have been furiously assailed and unjustly defamed, as selfish and infamous monopolists, who

8vo. pp. 16, Simpkin, Marshall, and Co.

exacted unreasonable prices to acquire extravagant profit. But may it not be truly affirmed, that they have generally supplied the public both well and cheaply too, if purity of quality, and abundance in quantity, compared with the price charged, be deemed a proper criterion of cheapness?

66

Notwithstanding the boastful, but delusive tales relating to the profitable nature of gas establishments, numerous are the instances of their being carried on for several successive years, without producing any profit whatever! The small dividends with the consequent depreciation in the value of the respective shares, show, that the majority of such concerns have not been profitable; and in various instances, this has actually been the result, where they enjoyed the advantages of the most economical management, as well as every improvement suggested by science and ingenuity to ameliorate their processes. But to persons who contemplate temporary objects only, it may be a matter of indifference if all the gas-lights, which are so generally beneficial, should be eventually extinguished, from the impossibility of continuing to light them at a serious loss: and this is a consequence, which recent events render probable at no distant period.

"But one or two striking facts deserve, and indeed demand very serious consideration. In the Act of Parliament for incorporating the Chartered GasLight Company (the first established), there was a clause which stipulated that upon due and reasonable application made to them for that purpose, on be half of any parish or parishes within the cities of London and Westminster, &c., they shall undertake to furnish, and shall furnish such parish or parishes respectively with a sufficient supply of inflam mable air, for the purpose of lighting the said parish or parishes, or part or parts thereof, with a stronger and a better light, and at a cheaper and lower price, all expenses included, than such parish or parishes, or part or parts of parishes, could be supplied with, if lighted in the usual manner, &c. Another clause enacted, that every contract or agreement entered into by any parish or parishes shall be null and void, if at any time the price charged for inflammable air, used in lighting the said parish, shall be greater than what at any time shall be

paid for lighting any parish or place situate within the cities of London or Westminster, or Southwark, with oil in the usual manner.'* This obligation was enforced in a subsequent clause, which enacted that if they admit, neglect, or refuse to carry into effect, and fulfil the provisions, &c., it shall be lawful for his Majesty to revoke and make void the said corporation, and deprive them of all their privileges.'

"Such were the conditions imposed by Parliament upon this company, which they not only fulfilled, but actually supplied so plentiful a quantity of gas to the street lamps, as afforded more than twelve times the light, which they usually gave, before gas was introduced! If this esta blishment had given only a little more light than what had commonly been yielded by oil, they would have strictly complied with the above enactments, but their conduct was characterized by more honourable feeling. To their liberality, at that period, the public are indebted for such splendid lights as now illuminate the principal streets; and having so effectively contributed to the improve ment of this important branch of local service and convenience, surely entitles them to some share of regard and adiniration, especially from those who enjoy the benefits resulting from their costly and meritorious exertions.

"When science and art have combined their powers to improve and extend the benefits of one of the most important inventions of modern times, and to diffuse its advantages over almost every part of this mighty empire, converting 'pitchy night' into a luminous resemblance of day,—the reflection is bumiliating, that the first symptoms of its decline should be exhibited in the metropolis,—the great emporium of British opulence and grandeur. But the fact is equally striking and lamentable, that the greater portion of those who commonly burn gas for their purposes, know scarcely any thing more of its properties, than its power to yield light

when it is inflamed!

"The statement of a few particulars relative to the principles and economy of gas-lighting may be useful, inas

Similar conditions are, I believe, enjoined in the Acts for incorporating all the other metropolitan Gas Companies.

much as they will enable any person to form a notion of what is essential for its purpose. In the early attempts to employ gas for obtaining light, it was burnt as it was distilled from the coal, and mixed with all the substances that rendered it so offensive as to excite strong prejudices against its use. It corroded the copper pipes conveying it to the burners, discoloured the bright surfaces of metals, and its odour was a serious annoyance. Its impurities being also deemed injurious to health, the separation of such noxious properties became indispensable. Various ingenious chemists, therefore, devoted much attention to effect so desirable an object the result of their experiments proved, that, by first cooling the gas by passing it through a large quantity of cold water, and afterwards forcing it through several vessels containing a mixture of lime and water, which machinery constantly agitated, the processes deprived it of all objectionable properties; so that it had not even one twenty thousandth part of any kind of impurity when it was conveyed to the public by the Chartered, City, Imperial, Phoenix, and other works heretofore established.

"As in the distillation of coal, different kinds of inflammable gases are evolved, which vary in their capability to yield light, the circumstance led to the making of many interesting experiments, for the purpose of ascertaining the proportion of luminous power possessed by each, and consequently their comparative value. The general result proved that the luminous quality, or, in other words, the brilliant light yielded by the gas, was in proportion to the quantity of carbon held in solution by the hydrogen, free from any admixture with other gases evolved in extracting it from the coal. If a large portion of the matter, which chemists call carbon, be combined with the gas denominated hydrogen, the quantity of light is proportionately great, especially when the other gases evolved with it in distilling the coal, are separated from it. The light produced by it in such a pure state is almost perfectly white, similar to the flame of an Argand lamp, or that of a fine mould candle immediately after being snuffed. This furnishes one certain criterion for judging of the qualities of gas; but its lu