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THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[April, 



nave and the two flanking towers, each of which is about 28 feet 

 wide and 112 high. The present termination is not original, the bat- 

 tlements and pinnacles being of much later date. As to the mode in 

 which they were originally finished it may be difficult to furnish a 

 satisfactory suggestion: but of that which remains it would be still 

 more difficult to convey an adequate impression. The simplicity of 

 its outline, the unbroken massiveness of its general feature, and the 

 rich and effective detail, respectively contribute to the grandeur of an 

 ensemble unsurpassed by any building of its date. 



The lower story has three doors into the church, and the second 

 five successive windows extending the whole width of the nave, with 

 a passage in the thickness of the wall. The second stage has an 

 equal number of windows, the heads of which are elevated towards 

 the centre to compose more readily with the gable, which is filled up 

 by a triple window and trefoil panel. The windows are of two lights 

 with trefoil heads and a trefoil in a circle above. Between the win- 

 dows are piers of several shafts with foliated capitals, and the 

 pierced pyramid or four-leaved rose; and the wall is very thick here 

 to receive the many shafts and deep receding mouldings with which 

 they are charged. The buttresses of the towers are broad and flat, 

 with shafts in square recesses at the quoins, and run the entire height 

 without diminution; the windows (except that some are filled with 

 louvres) corresponding nearly in form and date with those of the 

 central front. It is an interesting circumstance that the progress of 

 almost every change in this edifice can be traced at this moment with 

 no other guide than a little reflection, and with nearly as much clear- 

 ness as the most circumstantial chronicle could have recounted them. 

 The Norman nave, for instance, is shown to have extended as far 

 westward as the present, from the fact that the builders in making 

 their addition, left as much of the old work remaining as could be 

 rendered available ; and a portion of the old nave has thus been pre- 

 served, and the perfect coincidence of the joints of the piers with 

 those of the west wall, show that the formation of the fine arches 

 into the towers from the nave was predetermined in the design of the 

 architect, and not an afterthought as might on a cursory view be 

 imagined ; indeed, it may be noticed that the interiors of these 

 towers were finished with great care, and were intended to be entirely 

 open to view from the floor to the roof, where the walls are termi- 

 nated by a cornice and corbel-table. The moulded piers and arches 

 of the lower stories are very fine, and become plainer in proportion 

 to their remoteness from the eye. At each storv was a gallery of 

 communication, not only round the interior of each tower, but across 

 the front from one tower to another. 



I should have noticed that while the pyramidal flower is abundantly 

 used in the vertical lines and in the arches, the flattened uncut py- 

 ramid, usually called the nail head, is adopted with equal constancy in 

 the horizontal bands and dripstones ; yet there is not the slightest taint 

 of monotony discernible throughout. Beautiful as the principle of 

 construction here observed must be generally deemed, giving an ap- 

 pearance of the utmost solidity and strength, with a comparatively 

 small amont of material, it is to be regretted that there was a prac- 

 tical disregard of bond, and from the very inconsiderable proportion 

 of horizontal masonry the towers were divided by the windows into 

 four insulated vertical piers, with no adequate tie to meet the con- 

 tingency of a tendency to spread at the top. The subtle workings 

 of half a dozen centuries, however, manifest the necessity for a pre- 

 caution that was not contemplated bv the builder. 



It is, I think, pretty evident that the primary plan was a simple 

 Latin cross, without ailes. The transepts retain their original form, 

 except that chapels have been erected in the east walls, and arches 

 have been opened into the ailes of the nave; while the continuation 

 of the base mouldings, and other external decorations of the towers, 

 attest the absence of ailes at the time of their construction. The 

 present nave may be referred to the close of the 14th century, and is 

 a fine masculine example of that date. It has no triforium, but the 

 clerestory windows are large, and have a gallery running through the 

 piers. The wall ribs which exist indicate the purpose and form of 

 groined inner roofs; but it is to be regretted that this part of the de- 

 sign has never been effected ; and the external pinnacles were also 

 left in an unfinished state. 



Although the interior of this church cannot boast much of the rich 

 garniture of ancient monumeuts or mortuary reliques, its impression 

 and venerable aspect cannot fail to call forth our admiration and 

 respect; and the circumstance of its comprising fine decisive portions 

 of the consecutive styles including Norman and perpendicular, render 

 it an object deserving the careful attention of the architectural stu- 

 dent and antiquary. 



It only remains to notice a small building on the south of the choir, 

 a lower apartment of which has obtained some celebrity in modem 

 times as the bone-house, from the immense number and symmetrical 



disposition of the exuviaj of innumerable tenants of vet more cir- 

 cumscribed and darksome chambers, from which they "were ejected 

 some half century ago. They are now built in masses like masonry, 

 and exhibit an affecting display, to speak in the language of heraldry 

 of morts and saltirea argent. (There was a similar instance at Sligo 

 and another at Hythe.) This charnel house has certainly the charac- 

 teristics of extreme age, and the formation of the vaulting accords 

 with the earlier imitations of classic examples. The apsis at the 

 east, and certain external details also, attest its ancient foundation. 

 Immediately above is an apartment now used as the vestry, but for- 

 merly the chapel, to which the part just considered formed the 

 crypt. It is entered from the aile of the choir, end is of a verv sim- 

 ple character ; vaulted, and retains its ancient piscina. This building 

 has been deemed anterior to the body of the Minster : but when we 

 consider the casualties to which, from its position, it would have been 

 subject during the erection of so large a pile immediately contiguous, 

 it will probably be more rational to assign it a contemporary date. 

 May it not have been the lady chapel, or chancel chapel ? of which 

 there is a fine example now used as a school at the west end of Nor- 

 wich Cathedral, with a crypt below ; and it may be borne in mind 

 that both Norwich aud Ripon are Norman foundations without 

 crypts. 



THE EXPLOSIVE FORCE OF GUNPOWDER. 



The recent successful destruction of the Round Down Clift", at 

 Dover, by gunpowder, of which a full description was given in the 

 February number of our Journal, suggests a consideration of the ex- 

 plosive force of that agent, and of the best means of applying its 

 power. 



The circumstance which excited most surprise in the blast at Dover, 

 was the absence of all indication of explosive effort. That the cliff 

 should have been rent asunder by the force of the immense quantity 

 of gunpowder employed, was to have been expected ; but that the 

 effect should have been produced so gradually, without any report or 

 flame, or other usual accompaniment of an explosion of that agent, 

 appeared contrary to the ordinary conception of blasting operations, 

 and induced the operating engineers to imagine, at first, that the 

 charge had missed fire. The result has showji that Mr. Cubitt ad- 

 justed with great exactness, the amount of power to the resistance to 

 be overcome; and it has shown, practically, that the explosive force 

 of gunpowder, in any quantity, may be controlled, and brought to act 

 with a steady effort, like any other moving power. Had the quantity 

 of powder been much greater than it was, or had the same quantity 

 been placed nearer to the face of the cliff, there can be little doubt the 

 blast would have been accompanied by all the usual phenomena of 

 explosion. Had the quantity of powder been less, probably even to a 

 small degree, its force would have been either pent up within the 

 rock, without producing any effect, or it would have found vent by 

 blowing out the tamping. 



The force of ignited gunpowder, it is generally admitted, arises 

 from the sudden generation of a quantity of a permanently elastic 

 gaseous fluid, and the expansion of that fluid by the heat excited 

 during the ignition of the powder. The volume of elastic gas gene- 

 rated by the explosion of gunpowder, after it is cooled down to the 

 temperature of the atmosphere, has been determined by experiment 

 to be 244 times greater than the bulk of the powder exploded. It is 

 calculated that the heat produced by the ignition of the powder ex- 

 pands the generated gas into 1UO0 volumes at the moment of ex- 

 plosion; and that, consequently, fired gunpowder exerts a pressure 

 equal to 1000 atmospheres, or about 64 tons on the square inch. 



The 18,000 lb. of gunpowder used in the blast at the Round Down 

 Cliff" would occupy about 3u0 cubic feet, and the capacity of the three 

 chambers made to contain it was about 750 cubic feet. What space 

 was left between the tamping and the powder chambers, we are not 

 aware; but it would appear, from the published reports of the ope- 

 ration, that the tamping was rammed not far from the powder. We 

 will assume, therefore, the total space within which the gunpowder 

 was confined, to have been 900 cubic feet. This space would be three 

 times the estimated bulk of the powder, exclusive of the containing 



