double-reefed topsail and off bonnets of spencers; dirty rainy weather, and sea rising fast; moderating, and hauling to the W.N.W. in the evening.

15.-Moderate and cloudy; high N.W. swell; made all sail; 8h. 30m. lighted fires; increased to strong breezes, and squally, southerly, very thick, dirty, rainy weather.

16.-Daylight; cleared off, and saw the mizen-head; a fine breeze all day; running 10 and 11 knots.

17th.-At 1h. 30m. passed the Tuskar; 11 off Holyhead; 1 p.m. off Point Lynas; p.m. got a pilot and steam-tugs off N.W. light vessel; waiting for water.

THE WATCH TRADE.

In the table of restrictions and prohibitions with respect to the exportation of goods and merchandise generally from any port of the united kingdom to foreign parts set forth in 104th section of the Regulation Act of the 3rd and 4th William IV., cap. 52, the provisions of which are re-enacted in the 8th and 9th Victoria, cap. 86, of the past session, clocks and watches, that is to say, any outward or inward box, case, or dialplate of any metal, without the movement in or with such box, case, or dial-plate, in every instance, made up fit for the use, with the clock or watchmaker's name engraven thereon in a legible and permanent manner, are prohibited to be so exported from the united kingdom; and by the 31st section of the act of the 3rd and 4th William IV., cap. 53, re-enacted in the 32nd section of the 8th and 9th Victoria, cap. 87 of the past session, (we enumerate these acts thus fully and severally, because in the last session of Parliament the whole of the laws relating to commerce and navigation underwent a revision, repeal, or re-adoption, as was considered expedient,) any goods prohibited to be exported, which shall be brought to any wharf, quay, or other place for shipment, are forfeited. Some little time back a party entered at one of the outports, having an extensive and frequent communication with the Continent, a package containing severai dozens of British-made watch dial-plates for shipment to the Continent; which were, on examination, seized by the revenue officers, as prohibited under the several acts of Parliament above mentioned to be so exported. The party subsequently made an application to the authorities for their release, and, in order to avoid the application of the law in the matter with an undue severity, as the goods were about to be shipped in a regular manner, a reference was made to some parties in the trade, who, from their extensive deal

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ings in the trade, and experience in the matter, possessed a correct knowledge of the intention of the Legislature in respect thereto, with reference to the British manufacture of such articles; when it appearing that the dial-plates alluded to, which were enamelled on metal, fell within the prohibition, and were consequently liable to forfeiture, the application was rejected, and the goods ordered to be confiscated, and on a recent further memorial on the subject to the higher quarters, the order for their confiscation has been confirmed. The principal portion of the watch-dials in this instance were marked with a foreign maker's name and place of abode, and a few with that of the exporter, a foreigner, with the word "London" thereon. This latter infringement of the law, in so far as an evident intention existed of, when united to works of foreign make, giving them a British character abroad or at home, in direct opposition to the act relating thereto, would have been sufficient to cause their detention; but the advantage of exporting the dials or faces of watches, unconnected with any movements or works, at the same time regularly marked with the name and abode of a foreign maker, does not so readily appear. The fact is, that the faces or dials of watches, when not made of gold or silver, were formerly composed entirely of enamel, which enamel was imported into this country from the Venetian states for the purpose of manufacture; but, at the period of the disturbances on the Continent, its importation from that quarter was partially, and after a time, totally prevented. The enamel was subsequently composed in this country, but of a quality much inferior to that of the Venetian make. The attention of the trade was then directed to the substitution of a substance in lieu, and to answer the purpose of enamel, and by far the greater proportion of the watches now made, and especially those brought from the Continent, have their faces, when not of gold or silver, made of a prepared glass, manufactured expressly for the purpose, which looks well at first, equally with enamel, but is more liable to become injured or disfigured, and after a certain lapse of time loses its bright appearance, which is not the case with enamel. As may be supposed, the cost of an enamel dial is infinitely greater than one composed of glass, and is more valuable in proportion to its solidity and durability. It may be inferred, therefore, that, the intention of the shipper of the dials alluded to, which were composed of enamel, was to enable a foreign manufacturer to make his watches more valuable by the substitution of the better and more lasting material for his dial plates than that now commonly in -Times.

use.

NOTES AND NOTICES.

Suspension Bridges. Mr. Dredge has just completed two bridges in Ireland, one across the River Bann, county Down, the other over the Blackwater, county Tyrone. This last is for the Earl of Caledon, and is the second built across the same river-which Mr. Dredge has built for his Lordship within the last year, and the fourth he has erected within the last four months. Two of them are county bridges, and all of them are calculated to sustain a heavier load than can possibly come upon them.

The Iron Age.-It is now upwards of 5,000 years since Vulcan began business: but we question if he ever had so many orders as at present-never so many forges at work-never so many "artificers in brass and iron" to instruct. This is, indeed, "the iron age!" But the poets were not true prophets, who sung of the miseries of mankind during that age; for Midas has touched it, and, by a most potent alchymy, has turned it into gold! Witness the millions accumulated by those men of iron, the Guests, the Crawshays, the Thompsons, the Hudsons, and other millionaires of the present day. Industry, directed by science and skill, is, after all, the real alchymist; by exploring the bowels of the earth, and bringing up to light its mineral treasures, even of the coarsest kind, and by applying them to the commerce and convenience of human life, she enriches and improves the most extensive populations.-Boulogne News.

Dr. Payerne's Diving Bell.-Some short time since, Dr. Payerne descended in a diving bell, at the quay of Orsai, in presence of MM. Mallet and Frisseau, divisional inspectors, delegated, in connexion with him, by the French Minister of Public Works, to assist in experiments for the purification of air by his new process, when the following observations were made:-At 8h. 0m.-water below the mark, 0.76 pulsations per minute, 84; manometer, about one-ninth of the atmosphere? thermometer, 18. deg. At 8h. 12m.-the water below the mark, 0.71. Whilst descending there was merely felt a slight sensation about the eyes, which speedily ceased when the bell had reached the bottom. At 8h. 12m. some of the compressed air was let off, this immediately obtained an agreeable cool atmosphere. With closed cock, at 8h. 14in. -water, 0-80; pulsations, 81; 8h. 32m.-water, 0.71; thermometer, 22 deg.; manometer, 9; pulsations, 81. 8h. 47m.-water, 0-64; thermometer, 23 deg.; manometer, 9; pulsation, 81. No uneasiness whatever was experienced, the experimentalists merely feeling a little heated. A powerful ventilator in the square part of the bell caused a continual humming. 9h. 0m.-water, 0.61; thermometer, 24 deg.; manometer, 6; pulsations, 80. At 9h. 3m., the cock of the compressed air was opened, and the air found cool with an agreeable breeze. At 9h. 9m. the water being at 0·69, no more compressed air was left. At 9h. 17m.-water, 0.62; thermometer, 25. deg.; manometer, 6; pulsations, 82. At 9h. 39m.-water, 59; thermometer, 25 deg.; manometer, 6; pulsations, 82. At 9h. 49m. water, 0-59; thermometer, 25 deg.; manometer, 6; pulsations, 82. Similar experiments were continued till 11 o'clock, when the last observations gave-water, 0-57; thermometer, 254, manometer, one-seventh; pulsations, 86. These results are considered highly satisfactory, and confirmatory of the applicability of the process. For a description of Dr. Payerne's apparatus, see Mech. Mag., vol. xl., p. 1.

Increasing the Adhesion of Railway Carriages by Magnetism.-Dr. Wright, of Pittsburg, has made an application of magnetism to locomotives, which, if successful in practice will be of great importance. It is well-known (says the Pittsburg Gazelle) that lo

comotives of great weight are used upon our railroads, made so not for the strength or power, but solely for the purpose of procuring that degree of adhesion to the rail without which friction up-hill cannot be accomplished. Dr. Wright proposes to effect this adhesion by simply, at will, as the occasion may demand, converting by means of galvanism, the periphery of the driving wheel into a powerful magnet. Its application is very simple, and it is calculated that it will give each wheel an adhesive force of two thousend pounds additional to what it has from its weight; it follows of course, that a given force applied in propulsion, will be more efficient, as there will be less weight to be moved, and the tendency of weight having to run down hill instead of up will not have to be overcome in so great a degree, by mere force of steam.

American Iron.-A Liverpool merchant, who went through the American iron-works in August last, writes as follows:-"Mr. Wemslow, of Tray IronWorks, says that the owners of the Danville furnaces have contracted with the owners of the mills and forges to supply them with their pigs at 11 dollars per ton, or about 21. 5s. of our money; and they have contracted for a supply of coals, which are got close to the works, for 11 dollars, or 5s. per ton; and he says he has no doubt but that, in a short time, they will be able to make their pigs for 8 dollars per ton. You may judge for yourselves, therefore, what chance we have of long competing with these people. Charcoal blooms are now at 50 dollars, or above 101. per ton sterling." And he adds, in regard to wages-"The average wages of the workmen is about 3s. 6d. sterling per day, paid in truck at the employer's store, in provisions, clothing, &c., for which they pay 25 per cent., and in some cases higher, than they would buy them for at the regular stores."-Scottish Railway Gazette.

Wear of Railway Iron.-From some returns connected with the working of the Lowell Railway, in the United States, we are enabled to give a pretty correct account of the durability of railway iron, 56 lbs. to the yard. It appears that the first ten miles of the second track of this road was first opened in 1838, at which time an H rail was substituted for the fish-belly pattern, which had been found inadequate. From 1838 to July last, a period of seven and a half years, the total quantity of merchandise which passed over the line was about 720,000 tons, and of passengers and goods 120,000 tons-making a total of 840,000 tons, only one-half of which, or 420,000 tons, passed over the second track. In 1844, the company were obliged to remove considerable lengths of these rails, and substitute new; and, from the continuance of these repairs, it is highly probable the whole ten miles will be changed in the course of the next yearthus making its durability equal to 500,000 tons in eight and a half years; the generally estimated wear being 1,000,000 tons. The iron now being laid down is 63 lbs. to the yard, and costs the company about 4,700 dollars per mile. Dividing this sum by 500,000 tons, the amount of traffic which has worn it out, the result is one cent. per ton per mile; and the company receiving five cents. per ton per mile for their freight, leaves them four cents. per ton per mile to cover the other working expenses, interest, dividends, &c.-Mining Journal.

INTENDING PATENTEES may be supplied gratis with Instructions, by application (post-paid) to Messrs. Robertson and Co. 166, Fleet-street, by whom is kept the only COMPLETE REGISTRY OF PATENTS.

MUCH as we have published on the history of Screw Propelling, we find that the subject is still very far from being exhausted. We are now enabled, through the kindness of our ingenious friend, Mr. Bennet Woodcroft, of Manchester, to lay before our readers a document which carries the invention, as a patent subject matter, back to a much earlier date than is assigned to it in popular opinion. It is the copy of the specification of a patent for a screw propeller granted to one William Lyttleton, as far back as the year 1794. Mr. Woodcroft, who, as our readers are aware, is himself an ardent competitor for screw-propelling distinction, (see Mech. Mag. vol. xxxix., p. 293) has been led by the interest he takes in the subject to form a catalogue raisonnée of all the patents granted for, or relating to propelling, from as early a date as 1618, down to the present time, which he is about to publish; and the 66 scantling" we now present to our readers may be taken as a specimen of the value and utility of his researches.

liam Lyttleton, do hereby declare that my said invention of a certain machine, which I call the aquatic propeller, is described in the plan and description thereof hereunto annexed. In witness, &c.

Explanation of fig. 1.-a a a represent a hollow cylinder; b b b the sweeps fixed at right angles to the cylinder, and on an angle of 35° with the axis; cc the pivots of the axis on which it revolves in its frame when used; d d is a large sheave with an acute score to prevent the rope from rendering in it when in the act of turning, and has straps for the purpose of fastening it by screws to the inside of the cylinder and the cross bars at the end of it. (See figs. 3 & 4.) 1 1 1, e e e, are thin bars with straps (as at g g), which being secured to the ends of the cross bars (fig. 3, 2 2 2), and the edges of the sweeps support them in their pressure against the water; ƒƒƒƒ are the cross bars (see fig. 3) which are sunk into and secured to the ends of the cylinder; in the centre of them are the pivots cc, and the ends being turned and perforated as at 2 2 2, the thin bars (e fig. 1) are screwed thereto. The bars being made flattish should stand obliquely or parallel to the sweeps, the ends of which are fastened to them; r is part of the endless rope that passes over other sheaves to one at the end of a winch, which is to be turned by men, but may be done far more effectually by means of