LOCOMOTIVE POWEtt APPLIED TO CANAL TRANSIT.

A Short time ago an experiment was conducted on the Forth and Clyde Canal, of a novel and highly interesting nature, hy John Macneil, C. E., and consulting engineer to the Canal Company. It is well known that the haulage of boats on this canal has hitherto been performed by horses, the rates of speed being for the heavy sloops, brigs, &c, in the London, Dundee, and other trades, about one and a half to two miles per hour, when drawn by two or five horses, according to the state of the weather, and for the swift or passenger boats, between eight and nine miles an hour on an average, when drawn by two horses. The object of the experiment was to ascertain the possibility of using locomotive steam power to draw the boats instead of horses; accordingly a single line of rails upon blocks, like an ordinary railway, was laid down for a considerable space along the canal banks, near Rock 16l and a locomotive engine and tender, built by Mr. Dodds, having been brought down the canal and set on the rails, on the morning of the 21st, Mr. Macneil, Mr. Johnson, the canal director, and several engineersand gentlemen being present, the experiment commenced by attaching to the engine the towing line of the first passenger boat that made its appearance, and which contained upwards of ninety passengers, with their luggage.

There was a trifling delay in disengaging the horses and tying the line to the engine, but this was amply compensated when the Victoria briskly set off, and almost immediately gained a speed of seventeen and one-third miles per hour, which she kept up round two curves, and until the termination of the rails made it necessary to stop, amid the cheers of the delighted passengers. '1 his experiment was repeated during the course of the day, with each passenger boat as it came to the railed space, and with equal success each time. On one occasion a towing-rope, which was much decayed, got foul with a curb.stone and broke, but without causing the slightest inconvenience, except about one minute's delay. rl he engine employed being intended only for a slow trade, was not calculated to go at greater speed than eighteen miles per hour, but it was the opinion of all present, that with proper passenger-locomotives, a speed might be obtained equal to that upon the best railways, few of the latter possessing the advantages secured by the canal bank of a perfect level throughout.

The nature of the motion was highly

gratifying to all the passengers, being more uniform, steady, and smooth, than when the boats were drawn by horses.

Several of the heavy (masted) vessels were also taken in tow during the two days of trial, at the rates of three, three and a half, four, and five miles an hour; and, on one occasion, two loaded sloops, and B large waggon boat, were together attached to the engine, and hauled with ease at the rate of two and three quarters miles per hour, whilst only one-fourth of the steam was allowed to pass the throttle valve.

The foregoing statements render palpably apparent the immense advantages which might be gained by this new adaptation of steam power—a great economy in haulage expenses, as one engine might draw at least six sloops, which now would require from eighteen to twenty-four horses, and, if necessary, at double the present speed ; and a proportional increase of the important traflic on the canal, which might be reasonably expected.

Passengers would increase in great proportion when attracted by economy and speed of transport. 'I ho Union Canal might be traversed in two hours, and the Forth and Clyde Canal in one and a half, instead of four hours and three and a half, as at present, and this by only assuming sixteen miles per hour, though more might easily be performed, as the experiments have shown.

The foregoing is from the Glasgow Courier; it is much to be regretted that news papers in this country should be so deplorably deficient in scientific knowledge, as they almost all appear to be. We should have deemed the proposal of dragging barges through the water with a speed equal to that of trains on the best railways, sufficiently monstrous for any sober Scotchman; but when we are told that few railways possess the advantage of a perfect level throughout, "secured by the canal bank," although the experiment is stated to have been tried at the sixteenth lock, which implies considerable deviation from the horizontal line, we are inclined to suspect that the article was intended for the sister island, or the slick citizens of New York.

The subject of canal conveyance is one of great importance, and has recently occupied the attention of the French Academy. At the meeting of the Uth of October, the indefatigable M. Aragocommunicated to the learned assembly, a letter from Mr. Robinson on the subject of the experiments above described. It has been found that much advantage is obtained by maintaining a great speed in canal boats, so as to prevent the formation of the wave which, at low speeds, is observed before the boat, extending to, and injuring the banks, as well as impeding the progress of the vessel. These experiments have been repeated in France, and there is now a regular conveyance of this kind established on the canal de l'Ourcq, between Paris and Meaux. The horses employed must be well taught to start without hesitation, and continue without any diminution of speed ; for if the wave is once formed, it cannot be surmounted without great difficulty during the remainder of the passage. The steam locomotive possesses the requisite properties for this object; but it is a question worthy of consideration, whether, in many cases, it would not be more advantageous to place the engine in the boat, when an unobjectionable mode of propulsion is devised.

THE LIONS OF LONDON.

It has long been matter of regret to the lovers of science and art, that our national exhibitions were so inaccessible to the mass of the people, while in France, and other foreign countries, they were open to all who chose to frequent them. The narrow-mindedness of past days is, however, fast passing away; and partly through the influence of private individuals, partly by the provisions of government, and by the exertions of a society formed for the express purpose of affording the greatest possible facility for viewing these collections of the wonders of nature and art, the doors of many of the national exhibitions are now accessible gratuitously, at all reasonable hours, and many others will soon be thrown open. The publisher inserts here for the information of his numerous readers, especially such as may have occasion to visit London, a short account of the above most excellent society, and a list of the places already open to the public.

Sttielg for obtaining free access for the People to National Monuments, and to Public Edifices containing Works of Art.

President—His Royal Highness the Duke of Sussex.

Vice Presidents. The most Noble the Marquis of Westmilitter. Right Honourable Lord Hatherton. N. Ridley Coleman, Esq , M.P. Right Hon. Lord Viscount Lowther, M.P. John Angerstein, Esq.

Committee.
Jos. Hume, Esq., M.I'., Chairman.
Sir G. Sinclair, Bart, M.P.
H. T. Hope, Esq., M.P.
H. Droadwood, sq., M.P.
G. Rennie, Esq., Treasurer.
Lord Worsley, M.P.
Thomas W'jse, l'sq., M.P.
William Ewart, Esq.
O. Foygo, Esq., Honorary Secretary.

The object of this society is to procure for the people opportunities of intellectual recreation, and thereby lead them from dissipation or idleness to the cultivation of their understanding, the refinement of their taste, and a due appreciation of merit.

The society to consist of subscribers of one guinea for the first year, and five shillings each succeeding year.

The annual meeting of the society to be held in April or May, for the election of officers and for general business. Other general meetings to be held monthly, from November to July, and the progress made by the society duly reported.

Persons desirous of joining the society, or of giving information of Museums and collections of art or natural history open to the public, are requested to communicate with some member of the committee, or with the Hon. Secretary, 7, Manchester-street, Manchester-square.

Ladies are especially invited to join a society so conducive to the extension of civilization among the people. A list of the members will be published with the annual report.

The public are already admitted without any payment to

The Tower of London.

The British Museum—Monday, Wednesday, and Friday, and the whole of Luster and Whitsun weeks except Saturday, from 10 till 4; from May to September, 10 to 7; closed the first week in January, May, and September, and on Christmas day, Good Friday, and Ash Wednesday.—Young children excluded on holidays.

National Gallery — Monday, Tuesday, Wednesday, and Thursday, and the whole of Easter and \\ hitsun weeks except Saturday, from 10 till 5; closed for six weeks from the end of the second week in September, and on Christmas day and Good Friday.

St. Paul's—I each week day from 9 to 11, and from 3 to 4; and on Sunday from 10 to 12, and from 3 to 5. Visitors when in, may remain till dusk on week days.

East India House Museum—Saturday, from 11 to 3; all the year except in September.

Soune Museum — Thursday and Friday during April, May, and June only, from 10 to 4. Tickets must be applied for previously, and will be sent by post.

Society of Arts—Any day except Wednesday, to strangers and mechanics.

Hampton Court Palace—Arrangements are being made to admit freely Monday, Tuesday, Thursday, and Friday.

Kew Gardens—Pleasure grounds, Sunday and Thursday, free, from 12 till sunset, from Midsummer to Michaelmas; the Botanical Gardens and Arboretum every day, to intelligent strangers, from 1 to 3, at any season.

Dutwich Gallery—Each week day, except Friday, from 10 to 5 in summer, and from II to 3 in winter. Tickets to be had gratis from the principal printsellers in London. Children under 14 jected to.

Norwich Cathedral—One hour each week day, in addition to hours of service.

Bath Cathedral—At all times.

Doccr Philosophical Institution—Every Monday; principally Natural History.

Truro Museum—Daily; Alinerals.

Royal Dublin Society—Museum and ilotanical Gardens Tuesday and Friday; Gallery of Casts Wednesday and Saturday, from 12 to 4.

Edinburgh College of Surgeons' Museum— Four times a week—N»ble's Compendium.

DR. TURNBULL'S SUCCESS IN THE CURE OF Di.'AFNESS.

We paid Dr. Tumbull a second visit a few days since, and were extremely gratified. One case, in particular, came under our notice, in which, during a very short space of time—say ten or twelve minutes— we beheld a very obvious improvement. It was that of a young lady, probably about eighteen years of age, who had been both deaf and dumb from her birth. When she entered the room she oould not hear a syllable which was uttered, nor did she recognize the least sound, though two books were struck violently against each other, close by her ear. We never saw a more lamentable deficiency in the organ of hearing. The Doctor resorted to his usual mode of restoration,—namely, pouring a small quantity of some liquid into the ear, and stirring it round the interior with a piece of soft leather;—having continued this for about five minutes, he rejmated the experiment before alluded to, striking the book, however, much more

moderately; this his patient heard; the Doctor then spoke to her, and she readily replied by signs that she heard and understood him. The first letters of the alphabet were now spoken one by one to her, and she, after a few efforts, repeated them with very tolerable accuracy, proving, beyond a doubt, that a great improvement had taken place.

Another case was that of an interesting little boy, about six years of age, named Wells, who was likewise deaf and dumb from his infancy. Through the instrumentality of Dr. Turnbull, hearing was in a great measure communicated, and the little fellow was enabled to utter many words with the greatest promptitude and clearness.

The variety of cases which come under the Doctor's notice, are singularly numerous and pleasing. One at the present time is that of a respectable family from Scotland, five of whom are deaf; another, that of a young gentleman of fortune, whose relatives have recently returned with him from Paris, where he has been under some of the most eminent physicians; the sight was peculiarly touching when the youth returned to the room where we were sitting, to meet those of his friends who had not attended him whilst under the Doctor's hands ; perceiving how readily he replied to their first inquiries, they burst into tears of gratitude and joy, from a consciousness of the improvement which had been effected; another case—to mention no more—struck us as very peculiar; it was that of a man and his wife, who were both deaf and dumb, and whose only intercourse with each other was kept up by a rapid succession of signs made by their fingers. If we recollect right, they had three children, all deaf and dumb.

Highly pleased with what we have seen, we say to Dr. Turnbull, by way of concluding our remarks, "Go on, Doctor, and prosper!"

ANTHRACITE COAL.

At the recent meeting of the British Association, Mr. Player read the following paper on the application of anthracite coal to the blast furnace, steam-engine boiler, and smith's fire, at the Gwendraeth iron works near Carmarthen :—

The inconvenience of the fire choking for a long time baffled the experiments made on the subject, but it was at last obviated by heating the coal before it reaches the fire, which was accomplished by supplying it, without liny mixture of coke or bituminous coal, through a per

pendicular chamber placed centrally on the top of the boiler, with an opening about twenty inches in diameter immediately over the fire place. In passing through this chamber, by its contact with the plates, the coal acquires considerable heat, and descending by its own gravity, u the fire consumes beneath, replaces what has been burnt, by which means a regular supply of fuel is furnished, fit for immediate and complete ignition. Another inconvenience is also thus avoided, as fresh coal thrown upon the fire abstracts a quantity of heat from the fuel already in ignition, and checks the generation of ■team. The fire is never meddled with; there are no fire drawers; there is no current of cold air passing through the fines, and a very small amount only of draught is required. One engine worked serenty-two hours consecutively, during which time the grate neither choked nor dinkered; nor was a bar used for the fire, or did there remain any considerable remit in ashes. The coal was, in this instance, entirely anthracite (small, but not powdery)and tipped into the feeding chamber once every four hours. Water was also kept in the ash-pit, the steam from which, being decomposed by passing through the fire, the gas forms a jet of name, creating another active source of power. On these works, there are in action upon this principle, five smiths' fires, the tool maker's fire being blown by a 30-inch bellows only, whilst with this the largest squaring edges for the masons are made with ease. The coal is supplied through an upright brick flue, about three feet six inches high, two feet six inches long, and nine inches wide. The foundry has a similar arrangement, with merely the addition of a flue to take off the flame, the blast being cold, and worked by a 'mall water-wheel, and by which iron is re-melted, running very fluid, and yielding an excellent quality. An oven has also been built for the use of the workmen, heated only with small culm, which sue <*eds admirably.

ZOOLOGICAL SOCIETY.

Straxce, It True.—At the ordinary scientific meeting, on Tuesday evening, F- Wishaw, Esq, in the chair, the first fromunication read was a letter from Mr. Mackay, of the British consulate at Maracaibo, on a plant called Projojoy, in the country from which it was derived, and which arrives in this state from the strange metamorphose of an insect. In the insect which was described, some of the legs have

been already changed into roots, and in this state it was presented to the contributor. It was announced that it similar insect had lately been discovered in North Carolina. When this creature assumes the form of sn insect or animal, it is about an inch in length, and much resembles a wasp in appearance. When the insect has attained its full length, it disappears under the surface of the ground and dies, soon after which the two fore-legs begin to sprout and vegetate, the shoots extending upwards, and the plants in a short time reaching a height of six inches. The branches and the leaves are like trefoil, and at the extremities of the former there are buds which contain neither leaves nor flowers, but an insect, which, as it grows, falls to the ground or remains on its parent plant, feeding on the leaves till the plant is exhausted, when the insect returns to the earth and the plant roots forth again.

[We should feel part;cularly obliged to Mr. Mackay, if he would take this back and make some slight alterations in it, as it will be found difficult to persuade any one to believe it in its present state. This is not the first story of the kind we have heard ; and we should be glad if any of our readers could suggest a reasonable explanation of the appearances which have led to so strange a statement.—Em)

THE CHEMIST.

ACIDS.

NO. VI.

(See engraving, front page.)

Nitric acid is usually obtained by distillation of purified nitre with sulphuric acid, of which material different proportions are employed. The nitric acid of commerce, which is generally red and fuming, in consequence of the presence of nitrous acid, is procured by the distillation of one part of sulphuric acid with two parts of nitre: these proportions afford about one part of orange-coloured nitric acid of the specific gravity of 1.48. Upon the large scale, 112 lbs. of nitre and 5(1 lbs. of sulphuric acid, yield from 50 to 52 lbs. of nitric acid. .Some manufacturers employ three parts of nitre and two of sulphuric acid, and the London Pharmacopeia direct equal weights of nitre and sulphuric acid, by which a nearly colourless nitric acid is produced, provided the distillation be conducted at as low a temperature as possible. The distillation of nitric acid may be conducted upon a small scale in a