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blazing "Europa," brought confidence to all those who looked upon the soldiers in that imperilled ship. It is that spirit of duty which has, I believe, been throughout, and will continue to be, the guide of the British soldier.

"Not once, or twice, in our fair island's story,
The path of duty was the way to glory;
He that ever following her commands,
On with toil of heart, and knees, and hands,
Thro' the long gorge to the far light, has won
His path upward and prevail'd,

Shall find the toppling crags of Duty scaled,
Are close upon the shining table lands

To which our God himself is moon and sun."

In the tumult and conflict of opinion that is now raging over Europe, and in the kindred perturbations beyond the Atlantic, I can see no peace or security for the world, and for the advance of civilization, except in vindication of that reasonable, resolute, calm strength which represses aggression, and, happily, often prevents it from being meditated. In the military strength of England I see the best guarantee for the progress of civilization, the security of the world-I am almost tempted to add, in the military strength of England alone.

THE CHAIRMAN: Colonel Adair, I am afraid, from physical infirmity to-day particularly, and from want of experience in the post I occupy, that I am unable to do justice to the task which devolves upon me. At the same time I should be wanting in my duty to myself, to this meeting, and to this Institution, if I did not return thanks to you for your kindness in getting up these lectures, and for the admirable manner in which you have delivered them. [Applause.] The manner in which you have treated them would indicate deep research on your part, which could only have been induced by a thorough love of the subject; while in the delivery of them you have exhibited a fluency of language, and a perfect modesty of tone, which I must say does you the highest credit. It is only to be lamented that a gentleman with so thorough a military feeling as you possess should not be enrolled in our service. I feel thoroughly persuaded that such lectures as these must do good to all who hear them, in recalling to our minds circumstances which may have escaped us, and in inducing us to refer to our books for further information. I do not confine my observations to these particular lectures. To all the lectures that are given in this room I refer, feeling thoroughly persuaded that they must do an infinity of good. I could only wish there had been more persons present to hear this last lecture; but I suppose the weather, Ascot, and other circumstances, must be the cause of so few being present. In the name of the meeting, and of the Institution generally, I beg to return you our thanks, Colonel Adair.

Friday, June 21st, 1861.

MAJOR-GENERAL THE HON. J. LINDSAY, M.P. in the Chair,

THE DEFENCE OF PORTSMOUTH BY MEANS OF
ADVANCED SEA WORKS.

By W. A. BROOKS, Esq. C.E.

THIS subject necessarily involves a consideration of the state of Portsmouth, Langston, and Chichester Harbours, and I propose to treat it under the following heads :

Firstly. As to the present state of those harbours, and the causes which have produced the several impediments to navigation which are experienced.

Secondly. As to the means which are available for the removal of those impediments.

Thirdly. As to the result which will be produced by the construction of works for the improvement of the bars of Portsmouth and Langston Harbours, when considered in reference to the sea-approaches to those harbours and adjacent roadsteads.

Fourthly. As to the power of augmenting the accommodation or berthage for vessels of large draught of water.

Fifthly. As to the effect which those works will have in improving the military defences of Portsmouth Harbour, the roadstead of Spithead, and adjacent coast.

A study of the earliest published charts of Portsmouth Harbour down to the elaborate and beautiful one by Captain Sherringham, R.N. now in use, shows that the available depth of water in the sea-reach or channel leading to the harbour has at no time exceeded 2 fathoms, at low water of springtides. The survey by Captain Collins, the Hydrographer to Charles the Second, and those by Captains Mackenzie and Sherringham, all record an available depth of only 2 fathoms.

The position of this shoal, which by its presence reduces by one-half the general depth which would be otherwise available in the channel and on the sea-bar of Portsmouth Harbour, is very clearly defined in the three surveys referred to, and is shown to consist of a bank separating the deep pool of the harbour from the deep-water channel without. Thus, almost on the threshold of Portsmouth Harbour, there has existed, probably for several centuries, a barrier which is capable of being effectually removed by the scouring action of the tidal current when properly trained."

A year's work, and the expenditure of a sum, certainly under thirty thousand pounds, would raise Portsmouth from the position of a second to that of a first-class port.

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the Advanced Sea Works or Defences to Portsmouth and ooks in connection with a Fort on the Warner Shoal proposed by .B.

Spit and Horse Sands and on No-mans-land were projected by ional Defences.

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With the present available depth into Portsmouth Harbour of only 13 feet 6 inches at low water of spring-tides, and a flow of from 14 to 15 feet only, the enormous annual charges upon the nation which are entailed by reason of this deficiency of depth of water for the passage of ships of war may be readily accounted for.

If nature had been the sole cause of creating this great impediment to the free ingress and egress of ships of large draught of water, the attempt to remove it might be stigmatized by inexperienced people as a work which might be found to be useless, as "warring against nature;" but long experience convinces me that the cause of the existence of this shoal, the opprobrium of Portsmouth, is really due to the hand of man-to the formation of ancient quays within Portsmouth Harbour, which have had the effect of forcing the ebbing current to deviate from its normal course, which throughout its seaward flow below the present entrance into Portsmouth Harbour must have occupied the same channel taken by the flood current even at the present time, or have ranged close to or parallel with the present shore between Portsmouth and Southsea Point.

That the Admiralty is fully awake to the importance of removing this shoal is proved by the dredging operations undertaken for that purpose; but, inasmuch as this mode of treatment is simply removing effects without attacking and removing the cause of the existence of the shoal, it must prove unsatisfactory; firstly, on account of entailing an endless expense; and, secondly, because a large portion of the sand disturbed by dredging must be carried by the flood-tide into the harbour.

The paramount importance of increasing the present depth over this barrier fully justifies, however, the temporary remedial measures which have been hitherto attempted by dredging operations, even were they tenfold more expensive than is the case; and it only remains for me to point out the cause of the existence of this shoal, and the mode by which it may be removed effectually.

In the normal condition of Portsmouth Harbour approaches, or before the mouth of the haven was partly throttled by the construction of works on the spit of sand called "Blockhouse Point," and by those at "Portsmouth Point" on the opposite or left bank, there must have existed a broad and direct course into the harbour, with an available depth of not less than 5 fathoms at low water of spring-tides, because at that time the flood and ebb currents occupied the same channel. This condition ceased however with the erection of the works on the points of land above described, and the construction of the present quays and works on the Portsmouth shore of the harbour; which latter have the effect of deflecting the current of the ebb to the opposite or western side, and, but for the resistance it meets with there by the presence of the Spit sandbank, it would continue in the course thereby impressed upon it by the influence or direction of those quays, and would finally pass Southsea Point at a distance of about half a nautical mile to the westward of the latter.

Another result of this deflection to the westward of the current of the ebb-tide by the quays of Portsmouth is the production of a considerable eddy below Portsmouth Point, in which is deposited the sand which was previously held in suspension during the rapid course of the current out of the harbour, and thus is formed that long bank of sand which, tailing down

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