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power, will be unfolded as we proceed with our description.

The engraving on our front page exhibits the external elevation of the engine. is the carriage-frame; E the end of a circular boiler which passes under the carriage frame towards the steam-chamber A; La hopper to receive the fuel, (which is carried in two small baskets placed on the frame) whence it falls through a pipe in the centre of the steam-chamber A, into the furnace S; M the ash pit; D and N two working cylinders and their slides (one of each only is seen in the engraving); B the watertank; Can air-compressing apparatus, which acts on the furnace through the medium of a pipe that passes under the framework, and ends at K; N a pipe for the escape of the heated air; O the connecting rods which impart the action of the pistons to the wheels.

The boiler is made to contain about 45 gallons of water; the diameter of bach of the cylinders is 6 inches, and the length of the stroke 12.

The engraving on the second page of this week's Number, is intended to explain more particularly a very beautiful arrangement of the springs, to which this engine is mainly indebted for its superior steadiness when in action. The axle-trees are fixed to the iron rod A, and a sling C ist introduced to obviate that side action which would otherwise take place between the rod and the carriage-frame B. Again, to prevent the action of the springs from interfering ̧with the <action of the engine, the connecting rod, D, is placed as nearly in a horizontal position as possible; the connecting rods are moved by belloranks, E, which are connected by alings, F, with the piston rod. The springs, by the way, are of singularly excellent manufacture; they were made by Thrupp, and fully justify the celebrity which he has acquired in this peculiar branch of art.

The wheels are of the excellent description patented by Messrs. Jones and Co,,* and the choice of them by Messrs. Braithwaite and Ericsson is as

For a particular description of Messrs. Jones and Co.'s wheels, the reader may consult our 245th number.

strong a tribute as could well have been paid to their merits. From the peculiar manner of their construction they act with the least possible interference from the weight of the engine, and being perfectly cylindrical, bear equally with their whole breadth on the rails. The lightness for which these wheels are famed, is not in this instance so remarkable; "The Novelty" being itself in its main parts so light, as to throw other things in comparison with it into the shade. Of the total weight of 2 tons 15 cwt, we believe 18 cwt. falls to the share of the wheels.

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[To be continued in our next; when we shall complete our account of "The Novelty," describe one or more of the other engines, and add some general remarks:]

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DIALLING.

Sir, Observing in your September Part (1827) some questions in dialling by J. G." which have not I believe been yet answered, I take the liberty of sending the following sketch of the fundamental principles of the art, which, as it is altogether new, and contains sufficient to solve all those questions, may not be deemed unworthy a place in the valuable pages of the Mechanics' Magazine. Sketch of the Fundamental Principles of Dialling.

The equator may be considered the plane of a dial, and the stereographic projection of the meridians upon the equator will give 24 hour lines; and if the earth be supposed transparent and the axis opaque, when the sun comes upon the plane of any of these meridians, the shadow of the axis will fall on the opposite meridian; and so of the rest as the sun comes upon the plane of each of the meridians in succession, the shadow of the axis will fall on the opposite side.

Hence to construct an equatorial dial, nothing more is necessary than to divide its plane into 24 equal parts by lines divergent from the centre, fixing the axis perpendicular to the plane, and putting the names of the hours to their proper lines, and erecting the plane to an angle equal to

DIALLING.

the co-latitude of the place. There can be no sensible error in this construction, for the distance from the centre to the surface of the earth is but as a point compared with the distance of the earth from the sun.

But if a plane pass obliquely to the equator through the centre of the earth, or parallel to the horizon of some place not on the equator, i circumference will always be cut unequally by the meridians (1); and the axis will make with the plane an angle equal to the complement of its angle with the equator at the centre. Now the difficulty of this art lies principally in finding these points; on the circumference from which to the point where the axis is fixed, lines being drawn shall be the hour lines. Now when a plane is supposed to

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pass through the equater, and to fucline in any angle to its surface, it is obvious from the consideration of the sections of planes, that if from the points where the meridians cut the rircumference of the equatorial plane, lives be drawn perpendicularly to the oblique plane, the points where these lines cut the oblique plane being joined to the centre will give the true hour lines on the oblique plane or otherwise, if from the points where the meridians cut the circumference of the oblique plane, lines he drawn upon the equatorial plane perpendicularly to its surface, they will fall upon the hour lines at equal distances from each other. Upon a plane surface the lines on the oblique plane are easily found by an orthographic projection.

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In the above figure, if ABC repre⚫sent a quadrant of the equator, C the centre, and a, b, c, d, e, points where the hour lines meet the circumference, the points m, n, o, p, q, will be points found by the method of orthographic projection, through which from the centre the bour lines will pass for a plane, making with the equator an angle equal to BCD; or they are the *** game as would be found by drawing from the points a, b, &c. on the equator lines perpendicular to an oblíque plane, making with the equator an angle equal to the angle BCD.

The points m, n, o, p, q, are found as follows:-from a, b, c, d, e,,draw

perpendiculars upon BC; produce DC to E, and upon CE transfer the distances et, dw, cr, &c. to the points f, g, h, &c., and from f, g, h, &c. draw perpendiculars upon AC; transfer these perpendiculars along et, dw, &c. to the points m, n, &c., and they will be points through which the hour lines for the oblique'plane will pass.

The above observations contain all the general principles of the construction of dials, and will be found sufficient to an ingenious mind for the construction of all sorts of dials.

If the dial is to be vertical for a given latitude, its axis must evidently (from what has been said) make with

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its plane an angle equal to the colatitude

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New Sheathing for Ships.-It is stated in an counts from Van Dieman's Land, that a 76 gun

upon the plane, and this being done ship is now building there of fent, and 264 1875

hour are to be found by the orthographic projection in the manner explained.

And it may be remarked that, if the surface of the dial be curved, the axis must have the same position as if it were a plane, and the hour lines must be traced over the curve surface from the extremities of their delineations upon the plane.

to be sheathed with sheets of India rubber, which it is supposed will be not only impervious to water, but who'y free from any liability to foulness or corrosion

Ocean Wood is the naine or a new species of wood which has been lately used by Mr. Tom

kison, in the manufacture of piano-fortes. It 1

a sort of mahogany, and its name is supposed to have been given, from a fancied resemblance'its grain presents to the undulation of the sea. It is quite an unique in the English market, and for a single log Mr. Tomkison is said to have paid the enormous sum of 2300 guineas./1935) Painting on Glass-The Count de Noë, a

le is to process of France, professes, to have invented

These remarks enable us to immediately to the solution of questions. And it is evident,

(1.) That the positions of the hour lines will be different on dials having the same degree of obliquity for different latitudes. $.

(2.) That the axis of a vertical dial must make with its plane an angle equal to the co-latitude of the place.

(3.) That the axis of an east or west dial must be parallel to its plane.

(4.) If a dial decline or recline from the east or west, its axis (parallel to the axis of the earth) can no longer be parallel to its surface: therefore any alteration in the position of the same plane with the same index will produce a corresponding alteration in the time.

(5.) The enunciation of the fifth question is absurd; for the plane of an east or west dial at the equator will not be parallel to it, but perpendicular or parallel to the axis.

(6.) If an east or west dial be inclined in any angle to the horizon, it can no longer be an east or west dial, and therefore will not be cut in the same points by the meridians; consequently the hour lines will be differently posited, that is to say, this inclination will alter the time shown. Aug. 26, 1829.

B.

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of painting on glass, which equals the still discovered method of the ancients, Four pictu which have been lately painted by him on t

one of them for the chapel at the Luxembourg. are spoken of in terms of great praise by the Parisian critics.

The Art of Interweaving Figures on Cloth, by varying the arrangement of the warp, appears to have been early practised by the Egyptians. Herodotus (lib. iii. c. 47,) mentions a linen cuirass or breast-plate, sent by King Amasis to the Lacedemonians, with many figures of animais

woven into it; adding, as a thing extraordinary, that each thread of it, though apparently slender, I was composed of three hundred threads, all dis tinctly visible.

An Air Spout.-On the 15th ult. an extraordi nary phenomenon presented itself at Gorschoff in the Russian government of Pskow. Under a cloudy but tranquil sky, a violent whirlwind, accompanied by hail and a roaring noise, suddenly arose, and, passing over the town, completely devastated whatever it met in its passage, for a breadth of about eighty yards. Se veral buildings were totally destroyed, and others unroofed. Large trees were torn up by the roots, and carried to the distance of ten wersts. A considerable number of persons lost their lives, and a great quantity of cattle perished. In the other parts of the town every thing was perfectly calin, not a single bough being

shaken.

Preservation of Peach Trees.-A writer in the Southern Patriot proposes, as a way to prevent worms from injuring the trunks of peach trees, that a quantity of clay or compost be heaped round the roots, mixed with a little lime, marsh, or mud, while they are in the wood, that they may be suffocated before the fly can escape.

MISCELLANEOUS.

Price of Calico Fifty-three Years ago. The following memorandum was written in a Bible, now in the possession of a family at Rishton, Dear Blackburn, for the purpose, no doubt, of recording the period when the manufacture of calico was first introduced into this country.

15 September, 1776. Thonias Dixbury, of Rishton, near Blackburn, sold to Messrs. Peels, Yates, and Co. Ghurch Bank, two common-fine calico pieces for £5. 9i. Bd. These were the J. first calico pieces ever manufactured in this kingdom." Pieces of the same description are How sold for about 5s. 61. or er. each

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"THE ROCKET," LOCOMOTIVE STEAM ENGINE OF ***** MR. ROBERT STEPHENSON,

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146

GRAND MECHANICAL COMPETITION.

COMPETITION OF LOCOMOTIVE CAR-
RIAGES ON THE LIVERPOOL AND
MANCHESTER RAILWAY.

(Continued from our last Number.)
Seventh Day, 14th October.

It appears that after we left the railway on Wednesday se'nnight, and took our departure for town, Messrs. Braithwaite and Ericsson intimated to the judges, that as the joints of "The Novelty" which had given way, could not be restored to a working state before the lapse of at least eight days, and the prolongation of the competition was likely to be attended with great inconvenience to many parties, they would withdraw their engine rom any further trial, and "leave it to be judged of by the performances it had already exhibited." The manner in which this virtual conclusion to the proceedings has been announced by one of the Liverpool papers, is so distinguished by its fairness and liberality, that we cannot deny ourselves the pleasure of making the following, quotation from it on the subject:

(From the Liverpool Mercury.) "We may consider the trial of the Locomotive Engines as now virtually at an end. It is much to be regretted, that 'The Novelty' was not built in time to have the same opportunity of exercising that Mr. Stephenson's engine had, or that there is not in London, or its vicinity, any railway where experiments with it could have been tried. It will evidently require several weeks to perfect the working of the machine and the proper fitting of the joints, and under this impression, Messrs. Braithwaite and Ericsson have acted wisely in withdrawing, as they have done, from the contest.

"The course is thus left clear for Mr. Stephenson; and we congratulate him, with much sincerity, on the probability of his being about to receive the reward of £500. This is due to him for the perfection to which he has brought the old-fashioned locomotive engine; but the grand prize of public opinion is the one which has been gained by Messrs. Braithwaite and Ericsson, for their decided improvement in the arrangement, the safety, simplicity, and the smoothness and steadiness of a locomotive engine; and however imperfect the present works of the machine may be, it is beyond a doubt-and we believe we speak the opinion of nine-tenths of

the engineers and scientific men now in Liverpool-that it is the principle and arrangement of this London engine which will be followed in the construction of all future locomotives. The powerful introduction of a blast bel lows, the position of the water-tank below the body of the carriage, by which means the centre of gravity is brought below the line of central motion, the beautiful mechanism of the connecting movement of the wheels, the absolute absence of all smell, smoke, noise, vi bration, or unpleasant feeling of any kind, the elegance of the machinery, in short the tout ensemble proclaim the perfection of the principle.

"In withdrawing so honourable from the competition, Messrs. Braits waite and Ericsson have done they selves the highest credit; and they may rest assured that the scientific world will do justice to their efforts, and look with anxiety to a speedy completion of their elegant and compact engine prepared to bear the fiercest ordeal' which the judges may please to direct.".

"The Novelty" still remains at Liverpool, and Messrs. Braithwaite and Ericsson have publicly announced that as soon as it is repaired, and the cement of the joints sufficiently hardened, they will (with the leave of the Directors) complete the exhibition of its powers; and show that but for the accidents which it unfortunately met with, it was more than equal to the accomplishment of the task that was last assigned to it.

to come.

The prize is not expected to be positively awarded for some little time yet It appears that the gentlemen who were appointed to act as judges, have had only the name and not the usual powers of judges conferred upon them. All that they have been required and permitted to do is to make an exact report to the Directors of the performances of the competing engines; the Directors reserv ing to themselves the power of deciding which is best entitled to the premium. From the manner in which such reserved powers have been exercised in other cases (witness the conduct of the New London Bridge Committee to Mr. Gwilt), we should not be inclined to indulge in any favourable anticipations on the present occasion; but it so happens, that this competi tion has taken a course which makes

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