NOTES AND NOTICES.

The House of Commons' Committee on steam communication with India, have reported to the House that, in their opinion, the route by the Euphrates and the Persian Gulf is superior to every other proposed, for its " physical, commercial and political advantages," and they recommend that a grant of 20,000l. should be made by Parliament to defray the expense of giving it a fair trial. The distance from Bir in the Persian Gulf, where this line would commence, to Scanderoon in the Mediterranean, is stated to be much less than that between Suez and Alexandria. The Committee do not appear to have inquired at all into the merits of the route by the Cape of Good Hope. We are surprised at this, for whatever may be said in favour of either of the Mediterranean routes, as affording a quick, though not always sure, conveyance for letters, we think it is demonstrable that for goods, passengers, and troops, the line by the Cape is that on which steam may be employed with the greatest advantage. We alluded some time ago to a pamphlet, by the Messrs. Seward, C. E., in which this view of the subject is very ably advocated, and shall take an early opportu nity of bringing it again more particularly under the attention of our readers.

The Bengal Steam Fund Committee have advertised, in the Indian papers, that the steamer "Forbes" would start from Kedgeree, for Suez, on the 15th April; so that by this time the letters and passengers ought to have arrived in England. As great dissatisfaction had been excited in the other Presidencies at the preference given to Bengal, something may have occurred to prevent the ves sel's setting out at the appointed time. She was to carry only nine passengers :-three from Bengal, and two each from Bombay, Madras, and Ceylon.

M. Dupin has been so well pleased with his reception in England, that one of his colleagues, the Duke de Broglio, is about to follow his example, by paying his respects to the Lord Chancellor. Forthwith, of course, he will be taken to the Mechanics' Institution, and made an honorary member. The distinction will not, however, be so appropriately conferred as it was on M. Dupin, whose brother, Baron Chas. Dupin, is well-known as the introducer of similar institutions into France.

Turkish Mode of Illumination.-Every night the seraglio presented a different figure-a ship, the imperial cypher, the Sultan's ten oared galley, an immense star, a passage from the Koran, &c. These changes were sometimes effected during the same evening. This mode of illumination which is peculiarly Turkish, might well be adopted by Europeans; it is managed as follows:-A frame, from 20 to 40 feet high, is erected in front of the building to be illuminated; on the transverse beam small pulleys are adjusted, through which small lines are passed, to which the lamps are made fast at proper distances, and admit of being raised or lowered with the greatest ease, according to the outline of the figure to be formed. These lines resemble the warp of a web. Great extent can thus be given to the illumination at little cost-the rapidity with which a figure is transformed into another is surprising; in order to facilitate the metamorphosis, every line has marks, indicating the height to which it is to be raised, according to the exhibition intended. Every eminence can be taken advantage of-chimneys, minarets, trees, steeples and great room for the display of taste in the selection and variety of the figures may thus be obtained. From a Correspondent of the Times.

By the bill for the "Better Regulation of Chimney-sweepers and their Apprentices, and the Safer Construction of Chimneys and Flues"-as it

has passed the House of Lords-it is proposed to be enacted, that in future all partitions between chimneys or flues shall be of brick or stone, and at least equal to half a brick in thickness-that every breast, back, and partition, shall be built of sound materials, and the joints of the work well filled in with good mortar or cement-that every chimney or flue of greater length than four feet out of any wall, not being a circular chimney or flue of 12 inches in diameter, shall be in every section of the same not less than 14 inches by 9-that no chimney or flue shall be constructed with any angle therein, which shall be less obtuse than an angle of 120-and that every salient or projecting angle shall be rounded off 4 inches at least: Providing always that nothing in the bill shall prevent chimneys or flues being built at angles with each other of 90° and more, such chimneys or flues having therein proper doors or openings not less than six inches square." Should the bill, with these enactments, pass into a law, something will certainly be gained to the cause of humanity; but it seems to us, notwithstanding, to be conceived altogether in a very petty spirit of legislation. The shortest, and, at the same time, the only effectual way to put an end to the stifling and burning of infants in chimneys, is to prohibit absolutely and entirely the sweeping of chimneys by infants. Do but that, and people would soon, of their own ac cord, do all that it is now proposed to compel them to do, by a law, so nice and arbitrary in its provisions, that to enforce it generally and effectually will be impossible.

rooms.

A curious piece of machinery to measure time has been invented by Mr. Andrew Symington, watchmaker in Kettle. This timepiece is much more simple in its construction than the common eight day clock, requires only to be wound up once in twelve months, and being quite silent in its movements will be admirably adapted for bedIn this timepiece the pendulum and scapement are done away with, and a simple but efficient substitute is applied to the crown wheel, as in detents, which only allows it to revolve once in an hour, and has quite an uniform motion, without producing the smallest vibration in the machinery. Another important part of the discovery is a particular material for the pivots to move in, which is quite free from any cohesive quality, and requires no oil, therefore avoiding the irregular motion produced by the evaporation of the oil and other causes. Mr. Symington is about to construct a clock on this plan, to be sent to London, for the purpose of being exhibited there.Fife Herald.-The Mr. Symington here mentioned is a son of the late eminent William Symington, the father of modern steam navigation.

Mr. Andrews requests us to state that it was the printer who was in error in representing (page 15?) the difference between the scales as amounting to .34, it should have been, as suggested by Mr. Simms, .034. For, 17 links in 50 chains, or .17 = .034 of an inch. 50,000

Communications received from Columella D. T. S.-P. L.-P. μ.-Mr. Blackett-E. S. P. The Supplement to Vol. XX., with a Portrait of William Symington, is now ready, price 6d. also Vol. XX., complete, in boards, price Ss.

LONDON: Published by M. SALMON, at the Mechanics' Magazine Office, No. 6, Peterborough Court, between 135 and 136, Fleet-street. Agent for the American Edition, Mr. O. RICH, 12, Red Lion square. Sold by G. G. BENNIS, 55, Rue Neuve, Saint Augustin, Paris.

M. SALMON, Printer, Fleet-street.

MAGNETO-ELECTRIC RINGS.

Sir, The article of mine, which you have done me the favour to insert at page 191 of the last (June) monthly Part, is not connected with the article of May 24, at page 114, but refers to another intermediate communication, which I conclude has altogether failed to reach you. Besides the necessity of giving the article at page 191 a meaning, I hope what I now re-write and subjoin will be found to have sufficient intrinsic interest to entitle it to insertion, which I have to request for it as soon as convenient.

The advantages of the new method of the magneto-electric ring may be communicated to apparatus in which steel magnets only are employed, in any of the three following ways:-First, an armature of very large size is to be prepared, of the shape of fig. 1. The face ac b is to be made truly plain, so as to apply perfectly to the poles of a very large steel magnet; at c d a space is cut out of the armature, and its internal faces are finished very true. A disc, such as is described at page 191 (June Part, 1834), is then to be made of such a size as just to pass freely through the opening at c d; so also as that each face of the disc shall be in contact with an internal face of the opening. The disc is to be mounted on an axis, and must be capable of rapid motion; and some simple mechanism is to be attached to the axis, by which the poles of the armature wires may be disrupted on every successive intervention of iron or brass into the opening c d.

Now, analogy in general, and in particular some experiments, which I have gone through with very high magnetic powers, and which bear immediately on this subject-these authorise the conclusion that, when iron intervenes in the space c d, the magnetic current will pass directly through the space a db, and leave the rest of the armature almost whole uninduced; when, on the other hand, brass intervenes, the whole of the armature will evidently be permeated. At each successive intervention, therefore, there will be an almost total disturbance of the magnetic equilibrium in the armature, which is the end required.

It never reached us.-ED. M. M.

Fig. 2 represents such an apparatus ; M is a compound steel magnet of any mass; A an armature such as already described, and D D' is a section of the disc fixed in its place, and ready to revolve.

Figs. 3 and 4 represent different modes of development of the same principle. In these the armature is of the same shape with the magnet, and differs indeed only in being mounted with wire, and being made of iron. In fig. 3 the disc intervenes between one pole only of the magnet and armature. The other poles meet, and are in contact. In fig. 4 the disc works between both poles of the armature and magnet, and must be adopted with an additional prevention, namely, that iron may intervene between both pairs of poles at the same time, and also brass at the same time.

The last plan seems to promise the most complete disturbance of the magnetic equilibrium, but at the expense of great friction. The friction would be less in the third plan, and the fluctuation of the magnetic fluid perhaps not very much less violent and extensive than what would obtain in either of the other cases. An important advantage attends the last form of construction: it is that the armature, when necessary, may be used as an electro-magnet in charging or refreshing the component parts of the steel magnet. These forms of construction, however, although they offer results far beyond the power of those at present employed, are yet themselves just as far inferior in power to that of the electro-magnetic ring, in which electromagnetism alone is the agent. It would require an enormous expense and trouble to construct a battery of steel magnets equal in power to such a ring as I have described but supposing that it had been done, and a maximum steel battery had been constructed, the limit is arrived at, whereas the number of rings may be increased ad libitum, and one reverser will work them all.

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Before I leave the subject, sir, I beg to add one or two supplemental remarks on the construction of the reverser and of the ring. It may seem strange that I have insulated by glass the point of juncture of the magneto-electric poles; my reason for doing so was, that I think it yet remains to be proved that the magneto

electricity is altogether impenetrative. My experiments, on the contrary, lead me to conclude that it has a low degree of penetrative power; and as the reverser is to be employed with much higher intensities of that electricity than have yet been developed, it seems but reasonable to make a suitable provision. Analogy leads to expect a penetrative power, though very low in degree; but still a penetrative power. If, however, as I have ventured to anticipate, there should even be a striking distance established, where very high energies are being excited, this will not only justify my foresight, but render the central apparatus altogether unnecessary. In such a case

the poles of the armature coils could be used with the universal discharger, just as those of a powerful trough galvanic battery. I have also laid great weight on the advantage resulting from the solid continuity of the armature and magnet in the ring; in this, too, I think I am borne out by experiment and analogy. The theory of magnetism demonstrates that the magnetic fluid circulates with much more energy in a horse-shoe magnet when the armature is on the poles than when it is off; experiment also shows, that the more intimate the contact of the magnet and armature is, the greater is the development of magnetic energy. Consequently a magnet in the form of a segment of a circle will gain an increase of energy by the application of the supplemental segment to its poles, and the more intimate the contact of the poles of the two segments, the greater the mutual exaltation of their mutual engines: ergo, if the contact be that of solidity, the development of energy reaches the maximum. I conclude therefore, sir, that the degree of magnetic attraction developed between the two segments of the solid ring, exceeds what obtains between two similar separable segments, in the ratio which the partial contact that art can produce between two finely executed plane surfaces bears to the real contact which obtains in the transverse section of a solid. If we make a rough comparative estimate of the number of particles in actual contact in each case supposed, that ratio appears one of great inequality indeed; and so great must be the excess

of energy developed in one case over that produced in the other. In fact, the effect appears to be the very maximum of what nature is capable of producing.

It fills the mind with wonder and admiration to endeavour to conceive the mighty estuation that takes place within the solid iron, on every reversal of the galvanic current. If there be one fluid in agency, how subtle must it be to penetrate in an instant the interstices of such a solid, and that longitudinally; and, if there be two fluids, how much more intricate the action. Or, if there be no transmission of the fluid, but simply a change of disposition of the ultimate particles, by a vibration propagated through the mass, we are equally struck with wonder at the constitution of the mysterious bond of solidity which can endure such a concussion, nay, a succession of concussions, without dissolution. Place a quantity of jelly on a table, and watch how it is agitated on the slightest stir; and what difference is there, but one of degree, between the condition of that yielding, trembling mass, and that of the firmest solid we know of, while under the influence of heat, light, and electricity? Then, again, we boast of our means of accurate intelligence, of our insights into, and measurements of, the minutia of nature; but where is the eye that will detect these vibrations, or the hand that may measure their extent? Why, the very instruments we use are themselves in a similar state of vibration of particles, and fluctuation of form; and we ourselves, who hold them, maintain an apparent form, and perform our actions only by a succession of pulses. considerations show man in his true position, as one benighted in a wilderness, and having a small lamp. Its rays show him a few things immediately around him with tolerable certainty, and he guesses at many more; while the paths that lead to the dark and the unknown, radiate on every side from his position, and stretch out into infinity.

I am Sir,

Your obedient servant,

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