12« 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[April, 



or mediocrity. There is one defect attendant upon collegiate educa- 

 tion, which lias done that to damp the energies of students which no 

 other exertions have been able to remedy. Collegiate instiiiction soon 

 becomes so expensive as to come only within the range of a certain 

 class ; and while the selection is tlnis limited, theefl'ecton the students 

 is, that often possessing a competence, tliey have no other ambition 

 tlian to pass through their course with as little trouble as possible. It 

 must be conceded, on the other hand, that collegiate instruction effects 

 a considerable saving in time ; but it should be remembered, that seP'- 

 study, like a mechanical power, makes up in strength for what is lost in 

 time. Even in professions where knowledge is communicated by lec- 

 tures, the benefit of individual instruction begins to be appreciated, and 

 in the opening speech, ISst session, of tlie Dean of the Medical Faculty, 

 at King's College, he strongly recommended this course to be adopted. 

 The idea of teaching civil engineering solely in colleges we cannot but 

 look upon as absurd, and we know no means of expressing our views 

 more strongly than by repeating the words we used in the preface to our 

 last volume. 



•'The system of teaching by lectures, it has been found by ex- 

 perience, cannot successfully inculcate every thing ; and while it has 

 been abandoned at our older universities, in medical studies it is accom- 

 panied by demonstrations and clinical instructions, sucli as can never be 

 applicable to mines or engineering. We can have no dead railways to 

 dissect, no prepared veins and lodes to illustrate ; and although con- 

 struction niav be partially learned from models, yet it is in the open 

 field of practice that its application must be acquired." 



MEMOIR RELATIVE TO THE COURSE OF THE SHIN- 

 GLE ON THE COASTS OF SUSSEX AND KENT, AND 

 THE LAWS BY WHICH IT IS GOVERNED. 



By J. H. Williams, Lieut. Colonel, Royal Engineers. 



1. The general bearing of the coast from Beaehy Head to the 

 South Foreland, is from W.S.W. ^ south, to E.N.E. i north, by 

 compass. 



2. Shingle of a similar kind, produced by constant detrition of the 

 Beacliy Head Cliffs, and augmented by detritus from the Kentish 

 Cliffs, is found in large quantities all along the shore from Beaehy 

 Head to the South Foreland. 



3. It is ordinarily drifted along the shore from the westward to the 

 eastward, though subject to occasional interruptions. 



4. Wind and wave are the principal propelling powers. The 

 latter closely follows the course of the former, though at times de- 

 flected somewhat more southerly ; and a light air and undulation 

 are sufficient to carry the shingle in an opposite direction to a strong 

 tide. 



5. The shingle is invariably borne along in the direction of the 

 acute angle, which the waves form with the shore ; and the drift is 

 more or less rapid, in proportion to the strength and direction of the 

 wind, and the height and velocity of the tide. 



Fig. 1. 



The Shingle borne to the Easlwanl. 

 A, Angle of Wave. 4.5". KB. Line of Wave. 



6. The easterly and wonted course of the shingle is the effect of 

 the great prevalence of westerly winds in the English Cliannel. The 

 quantity put in motion, and the rate at which it is borne along, are 

 greatest on the Hastings shore, in a gale from the south-west, accom- 

 panied by a spring tide, when the wind and sea impinge on the 

 shore, at an angle of about forty-five degrees (sec fig. 1). 



7. When the wind blows from the eastward of south, a motion of 

 the shingle to the westward is speedily perceptible, and in a gale 

 from the south-east considerable quantities are moved in a westerly 

 direction. 



S. by E 



Fig. 3. 



.'^$^^^^^^%^^'~"^"***^'^'^'*^~*''^''"**^'^^"*^"" 



;2LAt_ 



The ShiiigV^ bui-ne lo tlic Weitwanl 

 liB, Line of Wave. 



8. When the wind sets directly on or oflF the land, the shingle is 

 quickly laid in ridges parallel to the shore, and there is no indication 

 of any drift of .shingle along shore at such limes. The truth of this 

 view of the subject will scarcely be doubted by any one who will 

 carefully watch the action of the shingle about a groin perpendicular 

 to the line of shore. 



9. The foregoing data clearly prove that the motion of the shingle 

 is strictly goveiTied by the direction of the wind and wave, and as 

 these prevail from the westward for nearly nine months in the year, 

 and storms are most frequent from that quarter, it follows that 

 shingle must be carried to the eastward in great excess. 



10. The force-propelling beach to the eastward may be considered 

 to be exerted between the west-south-west and south-by-west point*: 

 and therefore allowing for an action of the wave somewhat more 

 southerly than the wind, no harbour on this part of the coast should 

 be open to any point of the compass west of south, nor should the 

 relative positions of the pier-heads be such as to receive the set of 

 the sea between south and west. 



Fig. 3. 



South. 



The Shingle is moved np and down the Slope, but is neither carried to the East. 

 nor to the West. 



11. Any projcclion of magnitude must cause a pcnnanent altera- 

 tion in the form of the adjacent shore. The utmost care should 

 therefore be taken, in earrving out a pier or breakwater, that the new- 

 line of beach may lav as nearly as possible at right angles to the 

 point of the compass from where the wind blows, that causes the 

 greatest drift of shingle. By such a disposition, the most effectual 

 counteraction will be given to the easterly passage of the shingle 

 that can be obtained; but if this principle cannot be fully carried 

 out, let the nearest approach be made to it that circumstances will 

 permit. 



12. A chart upon a large scale will show that there are inflexions 

 of the coast where shingle must be heaped up. and cannot drift, at 

 the very times where it is borne along the general line in the greatest 

 quantities. The shores on each side of the Point of Dungeness are 

 examples. The extension of the Point to seaward, and its enlarge- 

 ment, may, it is presumed, be adequately accounted for by the theory 

 advanced in the preceding remarks ; and, assuming such to be the 

 fact, a very decisive corroboration of the system here propounded is 

 obtaiueil. 



