and Gloucester and Birmingham Navigation Company." The city is very ancient, and was famous for its struggles during the contests amongst the Britons, the Romans, and the Saxons. Its origin is attributed to the former. It was almost totally destroyed during the rupture between William Rufus and his brother Robert, although it had been "one of the noblest in the kingdom," according to Bede. Its imports consist mainly of timber and corn, and its exports of salt, iron, and bricks. Previous to the opening of the Canal, its goods were mostly brought to it in barges, which had transhipped them from vessels lying in the Severn. The labour and enterprise attending the formation of the Canal were accompanied by many vicissitudes and disappointments. No less than seven Acts of Parliament (including the one for the docks under notice) have been passed for it. The first was obtained in 1793. Then followed others in 1797, 1805, 1818, 1825, and 1825. The total capital authorised to be raised, under these various measures, amounted to £680,000, nearly all of which has been expended. The great drawbacks to its first success seems to have been the failure of the engineering department in getting a proper outlet. It was first designed to terminate at Berkeley Pill, but after five miles had been completed from the Gloucester end, and the capital expended, that scheme was thrown up. Ultimately, the one that succeeded had the foundation stone laid in July, 1818, by the Duke of Gloucester, who showed great interest in the work. The stone weighed four tons, and on it a brass plate was affixed, bearing the following inscription :-"To extend the advantages of commerce into the interior of the kingdom, and to facilitate the intercourse with foreign countries, the Gloucester and Berkeley Canal Company projected this work. The approbation of the most illustrious and dignified personages sanctioned the undertaking, and the countenance of his Royal Highness William Frederick, Duke of Gloucester, assisted by the noble House of Berkeley, was particularly evinced in graciously condescending to lay the first stone of this harbour, the fifteenth day of July, 1818. Long may it remain unmoved, a monument of national enterprise, a benefit to the proprietors, and a secure harbour for the commerce of the world!" In those infant days of engineering science, it seemed a wonderful feat to do such a deed, and hence the magniloquent strains in which the account of it is set forth. It is also stated in a local journal that, "immediately the ceremony was completed, the air was rent with acclamations, and old Sabrina's rocky shores re-echoed with the joyful shout of the surrounding multitude." There was no steam power in those days to facilitate the entrance of the vessels. The second vessel which entered was the Annie (300 tons), of Bristol. Some difficulty appears to have attended the approach of the ship, for it was a dead calm, and she had to be towed by boats. The ebb had set, and it

was only by getting a warp out to her, and hauling her along, that the vessel was safely passed into the canal. Another extract, from the newspapers of the period, is instructive, if not amusing, in showing the difference of opinion with regard to these things, which prevailed some fifty years ago. Now-a-days, we make docks having areas of even hundreds of acres, and see, unmoved, a leviathan like the Great Eastern, of 23,000 tons. It seems rather odd for us to read, regarding this small dock of eight acres, and still more diminutive ships, comparatively, that "The noble and imposing spectacle of a stately vessel of 300 tons burthen, in a style of complete equipment, as to rigging, &c., and decorated with a profuse display of colours and streamers, may naturally be supposed to have excited the admiration of the thousands who accompanied her throughout the whole line of the Canal; and the opportunity of viewing such a fine structure within the limits of the city, invites the attention of multitudes of spectators to an object which may very properly be classed as one of the most important achievements of human art." If Defoe had lived long enough to see it, he must have envied the writer of the last sentence. However, the Canal was, a success, and, contemporary with the great increase of our national commerce, has served to swell the profits of the ancient city. The docks, warehouses, &c., for corn, and timber yards, have been increased from time to time. The population has steadily advanced, though it cannot be said to be at the same rate as some of our more modern ports. In 1841, it amounted to 14,497, and last census to 18,330, within the municipal limits. The Parliamentary boundary being larger, gives a gross number of 31,804 in 1871. The arrival return of vessels, which is a good test of the trading development, shows as follows:

The number of vessels belonging to the port have, however, decreased;

The business, upon the whole, has increased, and, no doubt, there existed a necessity for the new docks at Sharpness, especially when it is considered that the flourishing ports of South Wales offer such advantages to ships for outward freights, and have induced many of the ships intended for Gloucester to go there and discharge. It is now hoped that the new docks will be sufficient to accommodate all the vessels intended for Gloucester for some time to come; and when the new bridge or tunnel (contemplated) is built across the Severn, it is anticipated that a large quantity of coal, from the Forest of Dean, will be there shipped. Moreover, the amalgamation with the Worcester and Birmingham Canal Company, will also give an opportunity of developing a carrying trade to the Midland Counties, and, to stimulate which, the directors are now considering an improved plan for expediting the traffic. At the half-yearly meeting of the shareholders, held at Gloucester on the 18th November last, the chairman said, amongst other explanations, and in moving the adoption of the report, "Nothing could more strongly prove that the geographical position of Gloucester was good, than the fact that during the last three years they had been enabled to carry on so large a trade in spite of their disadvantages, and that, too, with a gradual increase of How long it would take to fully develope their trade resources it was not for him to say, but he believed that in a few years they would witness great activity." The adoption of the report was agreed to, although a dividend of 13 per cent. was recommended. This was owing to the unproductive capital expended in the new works, which it is hoped will ultimately recoup the outlay.

revenue.

ERRATA. We are informed by the attentive Superintendent, Mr. Legge, that, in our notice of the Home for Apprentices at Liverpool, in the December (1874) number, an error was made in the designation of the ownership. It appears to be owned by Messrs. Balfour and Williamson, and that Messrs. Williamson, Milligan, and Co. merely make use of it on payment.-At page 1009, line 13, for the word "export" read "import" in the article on "Milford Haven," in the December number of this Magazine.

THE BESSEMER SALOON STEAMER.

N our November number we gave a criticism on the gyroscopic controlling apparatus for the Bessemer saloon, stating that the strictures we recorded represented the opinions of Board of Trade surveyors. We have in another part of this number announced the result of the Commission of the Institution of Engineers and Shipbuilders in Scotland on Safety-Valves. They endorse all that the Board of Trade staff had initiated in reference to safety-valves, and adopt the formulæ the surveyors had investigated and published. It is very creditable to both parties that such an issue is the final outcome of the loud complaints of these same engineers and shipbuilders. We have now to give an illustration of the opinion which Mr. E. J. Reed's colleague in the construction of the Bessemer steamer, entertains of the scientific ability of the Board of Trade officers. They said his gyroscope would have no more steadying effect at five thousand revolutions per minute than it would have if the material of which it was composed were carried in the form of pig-iron at the same height in the ship. Mr. Bessemer has thereupon decided to carry it in as near the form of pig-iron as is practicable, and we have no doubt he has taken a wise step in doing so. He has, on the 10th December, filed, at the Patent Office, a complete specification of this plan. The weight is in the shape of a heavy, idle grindstone of iron, and it is to be carried, as suggested by the surveyors, at about the same height and, if possible, without rotation. Our readers may think this notice a piece of burlesque, but we assure them it is sober fact, and, having probably had some share in bringing the fallacy of his former plan under the notice of the public, we will also tell our readers what is now thought of the way in which he is about to carry out the suggestion about the pig-iron. It is thought it will be quite safe and will give no trouble in inspection. It would not exceed at the best a force equal to one-thousandth part of the weight of the grindstone with a leverage equal to its radius. From that has to come off the force required to overcome the friction on its roller supports, and the residue, which might be carried, probably, for a penny postage, can be applied to operate the valve. This is, however, much better than the socalled gyroscopic plan first proposed, which the Board of Trade officers pointed out to be no gyroscope. Comparing the grindstone plan with the gyroscope correctly applied, the result is as follows. With a gyroscope and a grindstone of equal weights the radius of the grindstone equal to the radius of gyration of the gyroscope; at the very beginning of the roll the grindstone plan is most effective, but, after a portion of

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time, equal to that required by the gyroscope rim to move through an arc equal to radius in length, the two plans are equally effective, and while the inert grindstone does not at all increase afterwards in effective action, the efficiency of the gyroscope increases in direct proportion with the time from the commencement of the roll up to the instant when the vessel is upright. If each of the wheels were one foot in radius, and if the velocity of the gyroscope were only 50 feet per second up to onefiftieth part of a second, the inert grindstone plan would be most effective, but, after that instant, the gyroscope would become more and more effective until, when the vessel is upright, it would have fifty times the effective force of the other. Our remarks lead to the conclusion that the idle grindstone has only to be made large enough and heavy enough and without friction to prove a better steadier than the gyroscopic disc.

STEEL WIRE ROPES IN LIEU OF CHAIN CABLES AND TOWING HAWSERS.

NY invention that is likely to prevent loss of life and property at sea has at all times our careful attention. We have therefore lately inspected some steel wire ropes manufactured by Messrs. Bullivant and Allen, of Millwall, Poplar, London, for ships' cables and towing hawsers, which possess many qualities well worthy of consideration by owners of large ships and by the Committees of the Register Books of London and Liverpool. The pliability of these steel wire ropes is remarkable, as will at once be admitted by our readers when they learn that a rope of 120 fathoms of 5 inches in circumference, that withstands the breaking strain of 100 tons, is easily coiled on a reel, the outside measurement of which, with the rope on, is 4ft. 3in. in height, by 2ft. 6in. in width. One of the most important advantages in these steel ropes is their perfect uniformity of strength throughout. This is a particularly forcible fact, when compared with the untrustworthiness of our present ships' chain cables, in which, of necessity, the strength of the whole cable is only just that of its weakest link. The evidence given on this point by Mr. Thomas Chapman, F.R.S., Chairman of the Committee of Lloyd's Register, before the Select Committee, in June last, on "The Chain Cables and Anchors Bill," is of the utmost importance to shipowners. It shows conclusively that all the chain cables tested at public testing machines, which the Committee of the Register Book are authorised to work under licenses from the Board of Trade-viz., at Tipton,