1841.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL 



221 



tion can take place ; for matter does not move without an impetus. 

 Mr. B. then de facto, leaves the Major's thesis (with which I agree), 

 vrhere he found it, based on the solid and immoveable foundation of 

 truth. 



It is quite obvious that the Major has adopted the thesis that I 

 have, viz. 



1st. That wherever rivers, sluicing, or backwaters disembogue into 

 the ocean, either under a natural or artificial impetus, and run with 

 sufficient velocity to hold matter in suspension, and cause a conflicting 

 action with the waters into which they pass, there a bar is formed. 



2nd. That wherever there is an absence of egress waters, currents, 

 tides or sluicing power, and where no conflicting action ensues, there 

 no bar exists. 



3rd. That to these rules there are no exceptions throughout the 

 world, for wherever nature is placed under similar circumstances, she 

 is immutable in her results. 



" Here then we fix the universal cause, 

 God acts by general, not by partial laws." 



These primordial, universal, and indisputable facts are deduced from 

 an extensive field of observation of many years, and on various har- 

 bours, rivers, &c., during which time I have visited the Baltic, Gulf 

 of Finland and Bothnia, Russia, Prussia, Denmark, Sweden, Norway, 

 Jutland, Friesland, Holland, Belgium, France, Spain, Portugal, the 

 Mediterranean, Afiica's shores, and many harbours of the united king- 

 dom, — but all this devotion has been dealt with by Mr. Brooks in a 

 most summary way. and to refute my theory he has used the following 

 words, page 5, chap. (5, viz. : — "That the casual direction of the lower 

 reach, or the position of the mouth of the river cannot truly be as- 

 signed as the cause of the existence of a bar, is easily proved by ob- 

 servation on rivers s\ibject to great variations at the entrance, the bar 

 being always found to exist independent of the direction of the dis- 

 charge into the sea, this fact at once refutes the third and fourth 

 theories." — In this extract there seems to be two distinct facts, ;. e. 

 the casual direction of the lower reach, and the independence of a 

 bar, in the direction of the discharged waters, that is, he means that 

 the deposit or bar, does not occur in the direction or course of the 

 egress waters. With respect to Mr. B.'s assertion of the inde- 

 pendence of the bar, of the egress waters, I have much to say, if he 

 be correct, he has indeed " at once refuted my theory," and would 

 prove it to be a mere visionary and hypothetical deduction ; but I will 

 proceed to show the converse, and that he has committed, as in other 

 parts of his book, an egregious error. If the reader will turn to the 

 author's theoiy, subsequently here inserted, where he uses the icedgi to 

 aid his illustration, and where the battle with the elements occurs at 

 the first quarter flood, he will find it stated, "that in the conflict the 

 sand, or other materials, which it was ((. t. the effluent waters), capable 

 of holding in suspension previously to its encountering the conflicting 

 action of the flood tide, yields it to the latter, and when this takes 

 place the bar is/ormtd;" now observe, Mr. B. tells us that the material 

 which drops and forms the bar, is brought down into the ocean by the 

 egress or effluent waters, that as it advances onwards, (in its own 

 direction of course), it encounters the flood tide, and where it meets 

 that tide there the bar is formed ; so that Mr. B. himself destroys 

 the premises which he had the boldness to adopt for the annihi- 

 lation of my thesis. The positive and irresistable fact is, that all bars 

 are formed in the direction of the effluent waters, the latter are the 

 impetus to the matter held in suspension, and that matter m\ist fall in 

 the direction of the impelling power, as a shot from a gun, the ball from 

 the foot, or the deposit from the stream of the milldam. 



Passing on towards Mr. B.'s theory, I notice in chap. 2, page 19, 

 "pier harbours which though free from bar in their natural state, are well 

 knovin to become encumbered by them, on the introduction of the 

 scouring power," here I suspect he cast his eye southward on Lowestoft 

 Piers. Scouring power no doubt (this is my principle), causes a bar, 

 no matter whatever way or manner it is conducted to the sea, naturally 

 or artificially, whether there be piers or no piers. 



The commencement of chapter 11 is a mere repetition of my second 

 proposition, "That whenever a river or harbour approximates to 

 the condition of a simple inlet for the reception of the tide it would 

 have no bar." I endeavoured some time ago, in a conversation with 

 Mr. B., to illustrate this truism by a reference to various harbours 

 where the water did not pass into the sea, with a sufficient velocity to 

 disturb the bed, there no exterior deposit could take place; no matter 

 whether such a harbour be naturally or artificially constructed. Nor- 

 way,' Scotland, Ireland, Scilly Islands, Minorca, and Malta harbours, are 

 of the first kind ; Ramsgate, Margate, Scarboro', Cronstadt, Elsinore, 

 &c., the latter. 



In page 13, Mr. B. in noticing the geological features of the York- 

 shire coast, says, "That a residence of some years on its shores, and a 



close observation enables him to state, that those seas that break on 

 the outward platform, (the outer flat) are much heavier than those 

 which break nearer the shore." I bear testimony to the accuracy of 

 this fact, taught me in my boyish days by the boatmen, sailors and 

 fishermen, that on all flat shores, or in different elevated platforms (if 

 they must be so designated), the sea loses its force, where it is first 

 intercepted by the shore, and as it advances and rolls up the inclined 

 plane, so the concave dimension diminishes, till at last it finishes 

 in a mere ripple, or tiny billovr. 



I have now arrived at our author's theory, and it is multitin in parw. 

 "During the period of the first quarter flood, the current, in lieu of 

 being able to take its natural upward course, as in rivers where no 

 bar exists, is opposed, or effectually checked, by the effluent back- 

 waters ; the declination of the stream in the lowest division of the 

 river presenting a head which ensures a strong downward current, 

 long after the tide would have been able to maintain an upward course, 

 provided the backwater had a free discharge ; at this period the 

 flood tide, by reason of its greater specific gravity, occupies the lower 

 stratum of the tide-way, and like a wedge endeavours to force its 

 course up the channel, which it is unable to eftect, but merely elevates 

 the lighter effluent water, the lower strata of which, being checked 

 by tlie opposition of the tidal waters, yields to the latter the sand or 

 other materials which it was capable of holding in suspension, pre- 

 viously to its encountering the conflicting action of the flood tide; 

 where this takes place the bar is formed." 



Having shown that Mr. B. has attempted to refute my thesis by the 

 aid of a fallacious assertion, I now proceed to prove that he has based 

 his own on a sandy foundation. He commences this part of his work 

 by stating that the current, in the first quarter flood, is not able to 

 take its natural course upwards, as in rivers where no bar exists — 

 that is, where a bar does exist it is not able — and that this inability is 

 occasioned by the conflicting action of the waters (and which conflict- 

 ing action only exists where a bar is already formed,) and where this 

 fakes place (the conflicting action), there the bar is formed. So that, 

 in order to sustain his " novel theory" on the cause of bars, he first 

 must have a bar to produce the cause of a bar, and thus the eftect pro- 

 duces the cause, and with this mode of reasoning, illogical as it is, he 

 has attempted "at once," and with one fell swoop, nolens rokns, to 

 throw me overboard, and include in his general sweep, all who have at- 

 tempted by principle or practice, ancient and modern, a develop- 

 ment of the cause of bars. Mr. Brooks requires a backwater fall- 

 ing out of a sloping river, and that water to be opposed by a first 

 quarter flood, and a bar itself to produce a bar ; he appears not to be 

 aware that in various parts of the world bars have accumulated where 

 there is an entire absence of his causes, and not only at places " which 

 approximate to the condition of a simple inlet," but where the only 

 existing cause, amongst those which he assigns for a bar, is the egress 

 or scouring waters; examples of which we have in the Baltic, the 

 Black, and other seas. 



In my examination before a Committee of the House of Commons 

 in 1S26-1S27, on the proposed Lowestoft Harbour, I then stated "that 

 so soon as the scouring water should be applied as then proposed, a 

 bar would accumulate where no deposit or bar previously existed, 

 and if the sluicing were continued the harbour would be so blocked up 

 that small vessels only could enter at high tide." He need only refer, 

 to prove the accuracy of his prescience, to the present state of the 

 bar at that harbour, and the fact that about £15u,(jyj have been ex- 

 pended thereon, the entire of which has been recently oftered for 

 sale by the Loan Commissioners for £17,000, it being completely lost 

 as a harbour of refuge for which it was intended." 



It is an incontrovertible fact, that the greater the quantity of egress, 

 or sluicing waters, and the more rapid their course, the greater is the 

 exterior deposit. The Mississippi and other large rivers demonstrate 

 this fact — the entrance to that queen of rivers is most difficult in 

 the spring of the year, when the melting of the snow on the mountains 

 increases the quantity and rapidity of the egress waters, so as to carry 

 with them trees, earth, and other matter, all of which are deposited 

 on the extensive bar, at its outlet, and it does not again decrease until 

 after a long continuous dry season, when the quantity of egress water 

 is reduced. 



Mr. B. follows his "new theory" by stating, "that he might easily 

 extend his illustrations," and adds that the " direct tendency of the 

 whole period of the ebb, when unobstructed by the tidal currents, 

 must be to reduce the bar." This is really hypothetical. That the 

 ebb or outgoing waters have a direct tendency, and are the real cause 

 of all exterior deposits or bars,&c., I have asserted for the last 20 years, 

 the accuracy of which I will now attempt to prove. At the Neva, 

 Gulf of Finland, the Narva, Dantzic, the Danube, the Nile, and 

 many other places, the current, without intermission (there being no 

 food tide), is perpetually running out at the rate of six, seven, or eight 



2 H 



