Page:The Building News and Engineering Journal, Volume 22, 1872.djvu/90

 74 THE BUILDING NEWS. Jan. 26, 1872. and Alberti, nor can his influence on archi- tecture in Italy be compared to theirs. Nevertheless, he assisted largely in the for- mation of the purely Florentine style of civic architecture in which the character of the Medieval buildings was still to a great extent retained, although the members and details of the ancient school were introduced, as revived, especially by Brunelleschi. ‘The only fellow workers or pupils who succeeded to him appear to havebeen Pagno di Lapo Partigiani of Fiesole, who, besides several important works, designed, according to Vasari, the excellent Bentivoglio palace at Bologna. The influence of Michelozzo appears thus to have been rather of a conservative than pro- gressive character. He can hardly be said to have impressed a new style on the age, butrather to have modified the old one, and he is essentially the architect who gave to Tuscan domestic architecture that peculiar character which distinguishes it amongst all others, and which, though originating with Brunelleschi, found greater extension through Michelozzo, who may be regarded as the architect of the Medici family in the fifteenth century. Ee ROYAL INSTITUTE OF BRITISH ARCHITECTS. T the ordinary general meeting on Monday evening last, the President, Mr. T. H. Wyatt, in the chair, among other announcements ‘made by the Secretary, Mr. C. L. Eastlake, was that of the death of Mr. W. J. Booth, Fellow, of Torquay, which took place in December last; also that Mr. McKinnon, Fellow, had given £25 for the purchase of books for the library. THE ROYAL GOLD MEDAL FoR 1872. The President announced that the Council of the Tnstitute had that evening decided to recommend to the members the election of Professor Chevalier Frederich Schmidt, of Vienna, as the Institute Royal Gold Medallist for this year. The President remarked that Professor Schmidt was a most distinguished architect, and one who had shown himself by his works to be well worthy of the honour it was pro- posed to confer on him. Major-General Scorr, C.B., R.E., then read a paper ON THE CONSTRUCTION OF THE ALBERT HALL. In entering upon his subject, the author, after diselaiming any pretension to the title of an archi- tect, detailed the conditions which were imposed upon him in carrying out a work the general con- ception of which as to size and arrangement was originated by others. He produced the drawings and model, the work of the late Captain Fowke, which were put in his hands as the basis of the design that was to be executed, and drew attention to the modifications he had ventured to make in the building as executed. The original notion of such a hall was the offspring of the fertile brain of Mr. Henry Cole. The data prescribed for his (General Seott’s) guidance were as follows: Firstly, that the building should be of amphitheatrical form, and should seat with ease and comfort 6,000 or 7,000 persons. Secondly, that the interior accommodation for an audience should consist of (a) an arena which might occasionally be used for a promenade or exhi- bition; (b) some ten or twelve rows of seats above the arena, ranged in the form of an amphitheatre , (c) two or three tiers of boxes above the amphi- theatre seats; (d) a great gallery, open to the in- terior of the hall, running round the building between the interior and exterior walls, and top- lighted. Thirdly, that the entrances and exits should be arranged, like the seats, on the plan of the old Roman amphitheatre. Fourthly, that the facade should be of red brick and terra-cotta dressings. Fifthly, that the whole expense of the work should not exceed, for building works and expenses con- nected therewith, £175,000. With these instructions General Scott said he found himself in the possession of an advantage such as probably no architect ever enjoyed, or probably would care to enjoy. He had the advice of a committee of the following eminent architects, artists, and engineers—viz., Sir William Tite, Sir M. Digby Wyatt, and Messrs. Fergusson, Fowler, Hawkshaw, and R. Redgrave, R.A. At a preliminary meeting of the committee a question was raised on the first of the foregoing data. It was suggested that instead of the form of the Roman amphitheatre, that of the Greek theatre should have been taken as the model. The general form of the amphitheatre was, however, considered to be one of | the fixed conditions of the problem, but it is ques- tionable whether the results give reason to suppose that any other shape would have enabled an audience better to hear varied musical performances, or have afforded a more imposing effect. The general form proposed by Captain Fowke for the plan of his in- terior had semicircular ends, joined by almost parallel sides. The plan executed is a very close approximation to an ellipse, and is formed of ares of circles struck from four centres. By this means the difficulties in construction which the varying curvature of the ellipse would have entailed have been avoided. The major and minor axes between the walls which carry the roof are as 11 and 9 nearly. This form was decided on after careful consideration of the following experiments, opinions, and facts. The experiments of Saunders, described in his well-known work on theatres, showed that a person reading from a book could be equally well heard in the still open air at a distance of 92ft. in front, 75ft. on each side, and 31ft. behind. Sir C. Wren’s distances for the same position with reference to a speaker having a good delivery are, for an enclosed building, 50ft., 30ft., and 20ft. The dis- tances proposed by Captain Fowke were 204ft., 82ft., and 76ft., and in the Scala Theatre at Milan, the largest and most perfect lyric theatre existing, the distance from the curtain to the back of the boxes in front is 105ft., and the greatest half-width of the auditorium 4343ft. The distances for equally clear hearing in the open air are, according to Saunders, as 5, 4°5, and 2 for a person standing in front of, at the side of, and behind the speaker ; whilst Wren estimates the same distances in an enclosed building to be in the proportion of 5, 3 and 2. Captain Fowke apparently attributed much more influence than Wren to the effect of side- walls in carrying the wave of sound forward, for his distances are as the numbers 5, 2, and 1:8. The distances actually adopted in the ezse of the hall are 163ft. in front, 921ft. for the half-width at the broadest part, and 56ft. behind the position of a solo singer. These distances are very nearly in the proportion of 5, 3, and 2, the proportions given by Wren. Including the width of the picture gallery, the distance from the singer in front is 186ft., and the half-width 116ft. The modification of the plan of Captain Fowke to the plan carried out gave the opportunity, owing to the greater width of the building, of introducing the balcony, which was not a feature of Captain Fowke’s design, and which gives accommodation for 2,000 seats of a cheaper description, with a sacrifice of 800 seats in the amphitheatre and arena, The increased curvature of the sides also had collateral advantages as respects the stability of the roof. Although, from certain points of view, something of the grandeur of Cap- tain Fowke’s proposed arcade may haye been sacri- ficed, more than the equivalent of this loss has been gained by giving to the arcade a visibly solid wall to stand on, from whatever part of the interior it might be seen. The total length from outer wall to outer wall, as executed, is 266ft., and the total breadth from outer wall to outer wall 232ft. The length, breadth, and height of the interior do not materially differ from the proportions 5, 4, and 3; the actual figures are a length of 219ft., a breadth of 18dft., and a height of 136ft. It had been assumed by some critics of the acoustics of the hall that the velarium was an invention introduced to cover a defect found out only by experience. But its expe- diency, with the reasons for and against it, were freely discussed in the architectural papers in the beginning of 1869, when the roof was not yet fixed. This plan of obtaining a satisfactory ceiling was mentioned to General Seott at a very early period by Sir W. Tite, but it was really to Mr. James Wild that its adoption was due. In considering the mode in which the interior of the walls of the hall should be lined, three courses | were open: (1) to discard resonant mate- rials as far as possible; (2) to finish the walls with hard well-polished plaster, and to lay the floors with tiles; and (3) to line the walls with a resonant material. The latter course was adopted, i wood being the material employed, because, among } other reasons, the buildings most remarkable for their acoustic qualities have all been treated in this manner. Acting on these various reasons, and on the results of General Scott's many conversations with Mr. Roger Smith on the subject, the whole of the high wall behind the orchestra was covered with din. battens, carefully tongued together, with an air space of jin. between the wood lining and the wall. The whole of the wall of the picture gallery, with the exception of the pilasters dividing it into bays, was treated in a similar manner. The coving of the roof (with the exception of the cornice, which is of fibrous plaster), and all that portion of the roof- covering which is not of glass, is also of Sin. battens tongued together, and covered on the upper side with canvas stretched and glued upon it. As to the echoes complained of in the hall, General Scott said that listening for them had much to do with hearing them. They were now no longer heard of, because people went to listen to the musie and not for reflex sounds, which, doubtless, so far as they were appre- ciable, injured it. An important modification of the original design has been made in the arrangement of the staireases. It was originally intended that the space between the inner and the outer walls should be completely filled with stairs and landings, the one over the other, running spirally round the building, and all having their exit in one common corridor. Instead of this, a plan has been adopted which gives to each staircase, or pair of staircases, an exit into a separate crush-room, thus enabling visitors in different parts of the building to be kept separate. The provision made is at the rate of one staircase to 200 persons for the boxes and arena, and one stair- case for 300 persons in the baleony and _picture- gallery. The amphitheatre has one exit for every 250 persons. Each or these exits is Dft. wide. Sixteen of the staircases are 6ft. Gin. wide, and two of them 4ft. Gin. wide. Full advantage of the numerous exits of the building, however, cannot at present be made available, but it is in contemplation: to make roads both to Exhibition and Albert-roads from the south-eastern and south-western sides of the hall, and a Bill will beintroduced this session for connecting the hall with with the South Kensington station by pneumatic railway. Including singers and instrumentalists, the hall provides sitting ac- commodation for 8,365 persons. By putting the seats in the arena closer together, and by filling the gallery with raised seats, this number could be in- creased to 10,000 persons. There are 25 entrances, including the one from the Horticultural Con- servatory. The allowance for each amphitheatre seat is 3ft. by 2ft., the chairs turning on an aais. In the balcony the allowance is 2ft. Sin. by 1ft. Sin. The roof is perhaps the most interesting of the con- structive features of the building. In its first con- ception General Scott said he had the advantage of the counsels of Messrs. Fowler and Hawkshaw, and he was also assisted by the engineering ability of Messrs. Grover & Ordish, to whom were entrusted the preparation of all the drawings, as well as of the calculation of the strains on which they were based. The ironwork was all prepared by the Fairbairn Engineering Company. The whole of the main wall was constructed of hard Cowley stocks, set in Port- land cement with three parts of sand. Portland cement was also used for all concrete used in founda- tions, &e. The outer wall, built of bricks made by the contractor, was brought up to the level of the shallowest footings in Portland cement mortar of the above composition ; but all aboye this and all the cross walls and the walls within the main wall, were executed in mortar made in a mill with one measure of gray lime previously slaked, one measure of Port- land cement, and six measures of sand. The set of this mixture was sufficiently rapid to prevent any settlement taking place which might bring an undue strain on the terra-cotta dressings. It also enabled the main wall to be completed to its full height, and the roof to be commenced before the outer wail and cross walls were brought up, and in no instance did any such inequality of settlement from this cause take place as to produce fracture. The plastering was done with the selenitie mortar. As precautious against fire, hydrants are fixed at several points on each floor level, the whole being in communication with 30 tanks on the picture gallery roof, containing in all nearly 50,000 gallons of water. The tanks are supplied from a well in the rear of the building, and also receive the rainfall of the large roof. In the warming and ventilating arrangements General Scott had the assistance of Mr. W. W. Phipson. The warming is effected by hot-water pipes. The terra-cotta dressings were all supplied by Messrs. Gibbs & Canning, of Tamworth. General Scott said he was indebted to Mr. Gilbert R. Redgrave for the whole of the work connected with the prepara- tion of the terra-cotta, as well as for his general advice and assistance in every part of the work. Mr. Verity was charged with the preparation of the constructive working drawings. The red facing bricks were supplied by Mr. W. Cawte, of Fareham. Having described the mosaic frieze which forms so conspicuous a feature of the design of the hall, and the mode in which it was executed, General Scott brought his paper to a conclusion. Messrs. Lucas Bros. were the chief contractors. For clerks of the works he had Mr. Hemsley and Mr. Sankey. DISCUSSION. In the discussion which followed, Mr. Gilbert R. Redgrave detailed the mode in which the tessere