146 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[May, 



ing action imlh the traters of the ua, there a shoal or bar is inrariaUij 

 formed, and that the greater the velocity of the igries water, the larger 

 mil be the accumulation of shoal or bar. (See Fig. 1.) 



Fig. 1.— Plan of Dublin Buy and Kingstown llarLour. 



My second proposition is tliat, "wherever there is an absence of egress 

 or sluicing waters, or where the water passes into the ocean so as not to 

 convey matter in siispciision, and not to cause a confiding action with 

 the waters of the ocean, there is no bar or shoal, or exterior accumulation ; 

 and this proposition also applies equally to a natural harbour (see 

 Fig. 2.) as it does to one of artificial construction. (See Fig. 3.J 



Fig. 3.— Plan of Portrush Harbour, arlificially formed. 





In various parts of the world, harbours at the entrance of rivers 

 have been entirely, blocked up and lost, by the operation of sluicing 

 waters, and whether naturally, or artificially applied, the effects are 

 similar. I may instance the following places, viz. 



Wisbeach, Yarmouth (its north entrance), Winchelsea, Roniney, 

 Lowestoft, before referred to, Alexandria, the mouth of the Po, and of 

 the Nile, and many others which might be enumerated. 



The learned aiid great geologist, Baron Cuvier, states that " all 

 attempts to improve the entrance to harbours by scouring waters have 

 ever proved abortive, and brought science into contempt." 



The futility of such attempts the examples here quoted demon- 

 strate. 



Labelye, who wrote in 1747, said, "/ advise all persons to be on 

 their guard in attempts to construct locks or sluices on coasts, for besides 

 the erpence, they would be in danger of losing their harbours. 



Fig. 2.— Plan of Anlglass Harbour nalura'ly forincil. 



*a 'S 



— <^- 



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Among the places I have visited, there are many that exemplify 

 this proposition, the harbours being free from bars, and some of them 

 sufficiently capacious to contain the whole British navy. 



I will now refer to the evidence taken before a Committee of the 

 House of Commons in 1S3G, on Dover Harbour, and on the means 

 suggested by the Engineer for improving that harbour, who, in liis 

 evidence, says, " we are putting clown pipes ; and that is to carry 

 away the sluicing water, and render it more available by increasing 

 its force. The object has been that which every engineer who has 

 been consulted is desirous to obtain, and it appears to me that the 

 remedy, although an expensive one, cannot fail to be complete." 



Mr. Cubitt, (in answer to a question by the committee), said, 



"Suppose that these works do not do so much as it is expected, for 

 successful they must be to a great degree — " 



The attempted improvement has turned out a failure. I will next 

 give a short extract from the evidence of nautical and practical men, 

 who were examined by the same Committee, and the result has 

 shown that their opinions were better founded. 



Mr. Hammond, a pilot, speaking of the plans, stated the alteration 

 which had been made had not been effeclual. 



" Q. State your opinion to the Committee on the works now going 

 on. 



A. The bar will be more prejudicial and dangerous than it was 

 before. If cleared one tide, it will be filled up the next. 



Capt. Boxer, R.N., gave similar evidence, and said, " the works 

 will be a complete failure. 



The Honourable Captain (now Rear Admiral,) Elliot, gave similar 

 evidence, and said, " I consider, if the whole of the present plan was 

 completed, the Harbour, as far as regards a Refuge Harbour, would 

 be just as imperfect as it is at this moment." * 



After reading the above evidence, it must be clear to every candid 

 and reasoning mind, that whatever the right plan may be for the con- 

 struction and improvement of harbours, that plan has not yet been hit 

 upon by those engineers who have hitherto employed their talents in 

 this department, and as the greatest national interests are involved in 

 the question, and the safety and protection of our great maritime com- 

 merce, as, indeed, of our naval force itself, must mainly depend on tlie 

 efficiency of Harbours, in which ready refuge may be found in time of 

 need, no object can ])0ssess a higher claim upon public attention than 

 Harbours of Refuge ; on almost every part of our coasts the loss of 

 property and of human lives have become a reflection on our national 

 character. It is a lamentab'e truth, that while so many schemes of 

 improvement or benevolence are daily attracting the patronage of the 

 people of this kingdom, yet both the enterprize and the humanity of 

 the same people nave lain comparatively dormant on this subject, 

 which more than any other aliecfs our character and our interests as 

 a great mftritime nation. 



In this branch of practical knowledge we are, it is to be regretted, 

 much behind our continental neighbours, and prejudiciously shall we 

 find it so in the event of a war with them. 



In the session of 1839 I presented a petition to the House of Com- 

 mons, praying to be heard by a committee on the subject of bars, and 

 on the mode of constructing Harbours, free of bar or shoal at the en- 

 trance, and I was prepared to prove that the want of practical and 

 nautical engineers was the principal cause of failure of the attempts 



• See the [ublifhed evidence on Dover Harbour. Sjcssion, lt3(i. 



