wish well to their country, and to Bristol in particular; but whilst all enterprise is paralized by self-interest on the one side, and want of unanimity and energy on the other, there can be no hope of amendment, unless the fostering hand of government shall sign a release. It is said to be the intention of the Great Western Steam Navigation Company to try the question, by law, of the right of the dock proprietors to tax their vessel whilst lying in King Road, where she is necessitated to remain, because she cannot be received in Cumberland basin, on account of the entrances being too narrow to admit her entry every time she arrives from her Atlantic voyages. When she does enter the basin, she is lightened sufficiently to admit of her paddle boxes at the top of the tide, being risen above the walls. If the intention be seriously entertained, the issue would appear to be doubtful, on account of the state of the shipping trade of the port when the docks were formed; the accommodation, it will probably be insisted upon, being at that period sufficient:-the question for decision no doubt will be, whether the dock proprietors are bound to make such alterations and arrangements from time to time, according to the increase of size in ships, and whether the particular class of shipping called steamers, is to be understood as coming within the meaning of the act by which they hold their right of levying dues. The trial, as there seems no prospect of a speedy amicable settlement, would be desirable if only to define the extent to which the dock proprietors are liable; but it is really to be regretted that the matter cannot be arranged amicably, and that party interest should stand opposed to the general prosperity of the port. It appears that the Great Western Steam Company has formed a building dock near Cliff House, on the Bedminster side of the Avon, and has a very large iron steamer in progress, to be worked by a screw; at the same place docks are excavating for the repairs of large steamers. 11. I have just met with the following piece of hydrographical information, bearing on the subject of deposit. "The Phare de Rochelle states, that the sea is receding so rapidly from the bay of Bourg Neuf, that the remains of an English ship-of-war mounting sixty-four guns, which was lost on an oyster bank, called Les Retraites des Euvres, whilst in pursuit of a French ship, in 1752, is now to be found in the midst of a cultivated plain. In calculating the depth of the water where this vessel struck, with its present level, it will be found that the depth of the sea has diminished at least fifteen feet." This is at the rate of two inches, and a fraction of sedimentary matter deposited in a year; but as the accretion was no doubt principally of sand, not mud, the deposit would go on with less delay, because the gravity of a particle of sand is considerably greater than a particle of mud; besides, the whole baygulf of Biscay lies open to the swell of the Atlantic, and the surf, which is principally concerned in the above-mentioned accumulation, is very heavy. The Bourg Neuf lies between the rivers Loire and Garonne, and there are vast accumulations of sand in the vicinity. We can draw no comparison between this deposit and those which occur at King Road; but we may risk a general inference, that as it takes eighty-nine years to rise the bed of the ocean fifteen feet, upon a coast where everything conspires to assist the operation; the elapsed time necessary for elevating the bed of the anchorage at King Road fifty feet, where circumstances are not in combination for its acceleration, must be very much extended. Two miles and a half is the breadth of the level tract, north and south; its length, east and west, about five miles, and it lies fifty feet at the margin above the anchorage at low water: the period necessary for the accomplishment of such an accession to the land by deposits from the sea must be extended, we imagine, over thousands of years. We are perfectly alive to the care which it is necessary for the engineer to exercise in the erection of piers, especially where there are land streams; and have a general mistrust of the efficacy of such structures for remedying the evil of deposits. But here, if it be possible to anticipate results with any degree of truth, in a particular case, after the question is argued out in all its bearings, I should be inclined unhesitatingly to declare that a haven may be formed, between the Avon and Portshead, with solid stone piers,without the fear of more deposit entering than at present, and that as such deposit would be but trifling, it could with ease be removed, so as always to preserve a uniform depth within the haven. 12. Arches are recommended to be thrown in the piers, so as to admit the run of the tide through the haven to prevent deposit. So far from accomplishing such an object, they will defeat it, for this plain reason: that on either side of the stream of tide, eddies and still water would be formed, which are favourable to deposit, and a mud bank would be risen alongside the pier, and the vessels disturbed for the purpose of clearing it away; the vigilance of the port-master must be constantly exercised to counteract this effect. If my argument be correct, the labour of keeping the haven, formed by solid piers, from deposit, would be easy; I very much doubt whether the accumulation over the whole bed of the area at low water, would exceed three-fourths of an inch annually. It is not improbable, however, that the angle formed by the eastern pier outside, may be filled up with mud in a much shorter time than the bank would otherwise be formed. But the advance would subsequently resume its slow working property. This would not be detrimental in the least degree to the haven. Indeed it would have the effect of throwing off the current of ebb to the northward, and so prevent the apprehended rush upon the broadside of a steamer whilst entering the haven, and in this it would be serviceable. 13. The wooden breakwater, platform pier, or floating pier, as it is called, appears to be advocated by Lieut. Claxton, who probably has seen the plan of his friend Mr. Engineer Brunel, which nobody else has. I much doubt the utility of such a fabric, constructed how it may, in an open space of water, which is subject to any swell. In a river harbour, such as Hamoaze, it may answer in lieu of a stone pier; but as a shield for large steamers in any part of King Road, it would not realize expectation. All the direct allusion by Lieut. Claxton to the plan of Mr. Brunel is that the pier will not touch the bottom at low water. Something has since been said about iron tanks. In what way a communication with the shore is to be maintained at all times of the tide, and in all weathers, can alone be conjectured. We may conclude that the ingenuity of the engineer will be put to the test to effect this in a place where the rise of the tide is fifty feet. If it be by inclined plane, it would perhaps be necessary to throw out a vertical wall about sixty feet high from the shore at Portshead, to which one end of the stage would be fixed by swivel hinges; the other end resting on the float, which must be placed at a convenient distance from the shore to prevent the descent from being too great. Some difficulty would attend the management of this end as the tide rose, unless it be divided and hinged in proportioned pieces: at high water the stage would assume nearly a horizontal position; a chain suspension bridge, however, may be the mode intended to be adopted; either would be attended by difficulties, and require great attention. It is clear that it would never answer to place such a wooden float or breakwater, otherwise than in a line with the set of tide. There would be difficulty enough in steadying the huge thing in its place even then; and unless great care be taken in fixing the moorings judiciously, it might happen during the coincidence of a furious hurricane and tide in one direction that it burst its fetters and start off, up or down channel on a cruize. Chain cables I presume it would be moored with: now, chain cables have snapped under the extreme pressure of a wind end on; if a hurricane should blow transversely to the length of the float, with the lifting action of the accompanying undulation, would the supporting chains hold? Then how is the huge wooden structure (we are told 900 or 1,000 feet in length,) to be managed during the inconvenient rise and fall of the water to the extent of fifty feet? I presume by the supporting chains being eased and shortened in by machinery, according to the particular action of the tide: here will be incessant vigilance required to be exercised night and day, unless, indeed, in this age of invention, a self-adjusting machine be contrived, so as to supersede the manual labour that would otherwise be required. Let us only reflect upon the effect of a rotary storm which tears up by the roots, the tallest and stoutest elms of this vicinity; the wind veering round ten or eleven points, in conjunction with the run of tide, and then say whether a wooden structure would be likely to answer expectation. At high water, eleven fathoms, whatever sea or swell (I believe never very great,) thrown into the road would pass inshore under the float, and the reaction would strike against it, and force the steamers to haul off to save their paddle-boxes and wheels: and of course there would be a suspension of work for a time. It must be recollected that as water will break in more than ten fathoms, the undulatory impression must be felt at a depth considerably below the surface. Icebergs it is true afford shelter under their lee both from wind and sea, but this is occasioned by the immerged portion being six-sevenths of the entire height. Field ice also offers shelter from the sea, but it is only when the extent of surface compensates for want of height, that this occurs advantageously. The wooden float can bear no comparison with either. There is another point to be considered. It is an objection that perhaps may be ridiculed by the advocates of the wooden pier. In a work of magnitude, where the outlay will be considerable, and the benefits extremely doubtful, nothing should be left to chance. Projects fail principally because all contingencies which may happen are disregarded. A remote effect may prove as disastrous to a scheme, as a faulty mode of adoption immediately after its completion; in fact, it is the wisest plan to weigh all circumstances retrospectively, present, and those which may happen, before decision be given to any project. It is not improbable that in a few years, whether the wood work were coppered, or ironed below water, sea weeds, (which are here abundant,) muscles also in plenty, and other molluscæ, would accumulate in immense quantities, and in time bring the bottom of the float to the ground, and eventually keep it there, and thus swamp it altogether! If the adherence should happen to be one end only, that extreme would of course be gradually depressed, until finally as the weight increased it dipped like the vertical inclination of the needle! Supposing the cause of this strange "uptip" to be unsuspected, what a hubbub would be created among the "float sages" to unriddle the amazing phenomenon; if shod with iron it may be argued, perhaps, among the Phils that by some unaccountable means the metal had become magnetized, and the pole attracted by the earth's magnetism, so that if it went on increasing, the pier might at last stand on end, and so perpetuate the skill of the fabricator of such a wonderful piece of mechanism! Others might, perhaps, with more seeming probability conjecture that a huge whale had got jammed under the elevated end, and so depressed the other. But, if it sank uniformily and no longer retained its buoyancy, it might be attributed to the increased gravity of the wood in contact with the water; in fact, to anything rather than the true cause: seriously, however, these appendages must be looked after, whether the pier be formed of wood, metal, or stone, in a quiet place. It seems that on the score of economy a wooden pier is advocated; it generally happens that the cheapest thing is the worst, if not altogether worthless; indeed the reverse of economy usually results from buying or paying for cheap articles, the very reason assigned for its adoption seems decisive in its condemnation, if there were no other objections to it. My gallant brother sailor, Lieut. Claxton, says, " he thinks no fixed pier can or should be built." Unquestionably if it cannot, it would be the height of folly to attempt it; but, however, valuable his unprejudiced opinion may be, it is desirable that there should be more than one opinion given on the occasion, especially as the second objection to solid or to perforated stone piers is, the fear of the haven being soon filled up with mud. I think this apprehension needless, if the conservators do their duty, and compel the port-master to do his. I trust and believe, should the Bristolians complete a haven with solid piers, that, they would never have occasion to exclaim with Anaxagoras upon viewing the tomb of Mausolus;-"How much money changed into stone," but the reverse. Upon the whole I, free from prejudice or partiality, unbiassed by frowns or favours, no personal interest to serve, declare my opinion to be, that a wooden breakwater pier would not afford proper shelter during very severe weather, at high water, when there would be eleven fathoms; the estuary here being five miles wide. Besides, the accom The first relates to the great expense. modation for landing passengers at all times, and under all circumstances, would be extremely difficult of execution. I speak generally, of Mr. Brunel's plan I know nothing, and as Lieut. Claxton says, "nobody else," no doubt it is a very ingenious contrivance, agreeably to the well known talents of that clever engineer. 14. Why not a single pier running transversely to the set of the ebb, (the flood being non fluens here,) and a narrow causeway as a landing place down the sloping strand of 1,200 feet; so that the steamers could always lay on the western side, and after landing mails and passengers haul off and anchor in the road? This would not meet all contingencies, detention would probably follow in very stormy weather from the west and north-west, and delay in dark nights in landing and embarking passengers. To expect success, the plan adopted should be on a good scale, and otherwise complete; half measures, like second-hand clothes, are worthless, as well as expensive in the end. If the Bristolians have neither the spirit nor the means, or the one without the other, to execute a work of utility, that shall redound to their credit, this discussion is useless. I have heard that Capt. Cooksley, R.N.. who lives near Portshead, has given in a plan, with estimates, of an inclined plane alone, which shall embrace the points necessary; but of its merits or demerits I cannot speak; the idea of such a thing as an inclined plane for such a purpose, (I understand it is to be fixed and reach the bottom,) seems to my comprehension a little extraordinary; yet he may be justified, for I ought not to prejudge. E. ON THE LONGITUDES OF THE PRINCIPAL MARITIME POINTS OF THE GLOBE. By Lieut. Raper, R.N. Sec. R.A.S. (Continued from p. 380.) 171. Alijos, or Lobos, Is. Malasp. 1791, Lunars Vernacci and Echenique, 1807, 115° 38′ and 115° 41'. 172. Guadalupe. Id. South Point. Malasp. D.L. Monterey, D.L. C. St. Lucas 115° 37' 3° 34' 8 24 118° 19' 118 14 Espinosa adopts 112° 1', or 118° 18' Gr. Capt. of the Tuscan, 118 22 We adopt 118° 20′. 173. Port San Diego. Punta de la Loma. Malasp. Oltmann's II. Bauza, a M.S.S. Espinosa adopts 117° 19'. We shall follow Bauza. 174. Sitka. Arsenal. Bel. 1837. Moon culm. stars, 29 obs. [32s] D.L. San Franc. (Cove) 16ch. 2 passages 12° 53′ 16′′ Capt. Belcher adopts 9h. 1m. 8·1s. or 135° 17'0'. Which we shall follow. The lighthouse is south 78° west, 2,230 feet from Capt. 117° 16' 39' 117 17 34 135° 19' 42'' 135 17 16 |