CORRESPONDENCE
Concrete and Reinforced Concrete
To the Editor, The Architect & Building News.
Sir, — There are one or two points in the paper read by Mr. T. H. Bryce, and reported in your issue of December 9, that deserve more emphasis. The first is, that if uniformity in the quality of the finished concrete is to be obtained, the amount of water added in gauging must be varied according to the initial water content of the sand and aggregate. Within certain limits, the strength of the resultant concrete is decreased as much by the addition of too much water in gauging as if an equal quantity of cement had been omitted. This shows the need for an intelligent variation in the quantity of water used for gauging the concrete, according to the condition of the aggregate— which may vary in the course of a few hours in consequence of changes in the weather.
Mr. Bryce recommends that concrete buildings should be left from the shuttering, owing to a supposed tendency for cement renderings to peel off. The very great cost of preparing shuttering that will leave the concrete with a face suitable as an exterior finish is prohibitive to all but a few clients. There are many examples of concrete buildings finished externally with cement renderings which fully establish the suitability of this treatmenet when proper care is taken in the execution of the work, and particularly in obtaining a good bond between the first coat and the surface of the concrete.
Many architects are disappointed with the results obtained by the colouring of concrete and cement mixtures with added pigments, and the trend of practice is to obtain colour effects by the use of naturally coloured sands and aggregates which form the major part of the exposed surfaces and therefore dominate their colours. In the lighter colours the use of white Portland cement is of great value, and, of course, is an absolute necessity when a white effect is to be obtained.
A question which concerns many architects is, what will the appearance of these cement-faced buildings be a few years hence? The weather-scoured whiteness and soot-stained shadows give an added beauty to Portland stone, but it does not seem evident that cement facings will acquire these mellow tones. The bleached high lights of Portland stone masonry seem to result from a disintegration of the surface, which is not likely to occur with Portland cement.
As ordinary cement surfaces are porous, to an appreciable degree, it is obvious that their pristine brightness will be toned down by the absorption of rain and dirt, but it seems likely that this will only result in a uniform dinginess rather than the acquisition of bright high lights, half tones and sombre blacks, which, in our stone-faced city buildings, have been the inspiration of so many artists.
A conclusion that seems obvious is that cement surfaces should be made impervious, so that although dirt may be deposited upon them it is not carried inwards by the absorption of water, and the building may, therefore, acquire some high lights when the surfaces of the more exposed portions are cleaned by the scour of the weather of the superficial deposit of dirt. — Yours faithfully, L. Edmund Walker.
3 Mount Street, King’s Lynn.
A City of Towers
To the Editor, The Architect and Building News.
Sir, —With further reference to Mr. Edward Unwin’s criticism on Mr. Hood’s proposal for a City of Towers, I have received a letter from Mr. Hood, who feels that he is too far away to enter into a con
troversy. He makes some remarks, however, which may be of interest in this connection.
“Mr. Unwin apparently has never heard of the latest developments in elevators. The possibility of running one or more elevators in the same shaft, like several trains on the same railroad tracks, is not a speculation, for one of the largest elevator companies in the world is ready to start to-morrow on such an installation, provided a building high enough to warrant it is projected.
“His comments on traffic do not go much further than his comments on elevators. Certainly increasing the amount of available street area would not make conditions any worse. Mr. Unwin is a very brave man to define so concisely the limitations of traffic under such new conditions. For my own part, I am inclined to believe that someone will have the intelligence to find a practical use for the extra space.
“There is a suggestion in Mr. Unwin’s last sen
tence that should not be overlooked. Why not take up my scheme with Mr. Heath Robinson and see what he can get out of it as a Town planner? And, in the meantime, Mr. Unwin might take up some of the humorous works of Mr. Heath Robinson! ”
Yours faithfully,
Howard Robertson. 36 Bedford Square, W. C. l.
Competition News
Loughborough College Scholarships
The governors invite applications for the award of five open scholarships in the Faculty of Engineering — each of the value of £75 — open to British subjects, not less than 16 years of age on October 1 next, in any part of the Empire, and tenable at the college for the Diploma Course. An entrance examination for the session 1928-29 will take place on April 24, 25 and 26, 1928. Particulars and application forms may be obtained from the Principal, Dr. Schofield, of the College, Leicestershire, England.
Personal Notes
Mr. A. C. Carter, Mrs. E. M. Gabriel, Mrs. M. R. Mitchell, Mr. G. H. Paulin, A. R. S. A., and Mr. H. Tyson Smith have been elected associates of the Royal Society of British Sculptors.
Mr. William Hunter, Mr. Alexander Jamieson and Mr. William T. Wood, R. W. S., have been elected members of the Royal Institute of Oil Painters.
An enquiry has been held, on behalf of the Council of the British Archælogical Association, by Miss Rose Graham, M. A., F. S. A., and Mr. P. M. Johnston, F. S. A., F. R. I. B. A., into the merits of a claim that a small chapel or cell at Luton Parish Church, about 8 feet long and 3 feet wide, was a “Pyx” chapel,
or connected with a receptacle for the reservation of the Sacrament The referees find the claim to be unfounded, the term “Pyx” having nothing to do
with the Sacrament, but with the current coinage of the realm, as at Westminster Abbey, being, moreover, unknown before the Reformation. The carvings which were supposed to confirm the sacramental idea are also found to be a punning allusion to part of the name of Vicar Barnard, a former incumbent.
Penryn is to have an all-concrete road, the local authority having decided to adopt this form of construction in Commercial Street, to withstand the damage caused by the spring tides which, normally, flood the main roads each year. The cost will be £2, 800.
Concrete and Reinforced Concrete
To the Editor, The Architect & Building News.
Sir, — There are one or two points in the paper read by Mr. T. H. Bryce, and reported in your issue of December 9, that deserve more emphasis. The first is, that if uniformity in the quality of the finished concrete is to be obtained, the amount of water added in gauging must be varied according to the initial water content of the sand and aggregate. Within certain limits, the strength of the resultant concrete is decreased as much by the addition of too much water in gauging as if an equal quantity of cement had been omitted. This shows the need for an intelligent variation in the quantity of water used for gauging the concrete, according to the condition of the aggregate— which may vary in the course of a few hours in consequence of changes in the weather.
Mr. Bryce recommends that concrete buildings should be left from the shuttering, owing to a supposed tendency for cement renderings to peel off. The very great cost of preparing shuttering that will leave the concrete with a face suitable as an exterior finish is prohibitive to all but a few clients. There are many examples of concrete buildings finished externally with cement renderings which fully establish the suitability of this treatmenet when proper care is taken in the execution of the work, and particularly in obtaining a good bond between the first coat and the surface of the concrete.
Many architects are disappointed with the results obtained by the colouring of concrete and cement mixtures with added pigments, and the trend of practice is to obtain colour effects by the use of naturally coloured sands and aggregates which form the major part of the exposed surfaces and therefore dominate their colours. In the lighter colours the use of white Portland cement is of great value, and, of course, is an absolute necessity when a white effect is to be obtained.
A question which concerns many architects is, what will the appearance of these cement-faced buildings be a few years hence? The weather-scoured whiteness and soot-stained shadows give an added beauty to Portland stone, but it does not seem evident that cement facings will acquire these mellow tones. The bleached high lights of Portland stone masonry seem to result from a disintegration of the surface, which is not likely to occur with Portland cement.
As ordinary cement surfaces are porous, to an appreciable degree, it is obvious that their pristine brightness will be toned down by the absorption of rain and dirt, but it seems likely that this will only result in a uniform dinginess rather than the acquisition of bright high lights, half tones and sombre blacks, which, in our stone-faced city buildings, have been the inspiration of so many artists.
A conclusion that seems obvious is that cement surfaces should be made impervious, so that although dirt may be deposited upon them it is not carried inwards by the absorption of water, and the building may, therefore, acquire some high lights when the surfaces of the more exposed portions are cleaned by the scour of the weather of the superficial deposit of dirt. — Yours faithfully, L. Edmund Walker.
3 Mount Street, King’s Lynn.
A City of Towers
To the Editor, The Architect and Building News.
Sir, —With further reference to Mr. Edward Unwin’s criticism on Mr. Hood’s proposal for a City of Towers, I have received a letter from Mr. Hood, who feels that he is too far away to enter into a con
troversy. He makes some remarks, however, which may be of interest in this connection.
“Mr. Unwin apparently has never heard of the latest developments in elevators. The possibility of running one or more elevators in the same shaft, like several trains on the same railroad tracks, is not a speculation, for one of the largest elevator companies in the world is ready to start to-morrow on such an installation, provided a building high enough to warrant it is projected.
“His comments on traffic do not go much further than his comments on elevators. Certainly increasing the amount of available street area would not make conditions any worse. Mr. Unwin is a very brave man to define so concisely the limitations of traffic under such new conditions. For my own part, I am inclined to believe that someone will have the intelligence to find a practical use for the extra space.
“There is a suggestion in Mr. Unwin’s last sen
tence that should not be overlooked. Why not take up my scheme with Mr. Heath Robinson and see what he can get out of it as a Town planner? And, in the meantime, Mr. Unwin might take up some of the humorous works of Mr. Heath Robinson! ”
Yours faithfully,
Howard Robertson. 36 Bedford Square, W. C. l.
Competition News
Loughborough College Scholarships
The governors invite applications for the award of five open scholarships in the Faculty of Engineering — each of the value of £75 — open to British subjects, not less than 16 years of age on October 1 next, in any part of the Empire, and tenable at the college for the Diploma Course. An entrance examination for the session 1928-29 will take place on April 24, 25 and 26, 1928. Particulars and application forms may be obtained from the Principal, Dr. Schofield, of the College, Leicestershire, England.
Personal Notes
Mr. A. C. Carter, Mrs. E. M. Gabriel, Mrs. M. R. Mitchell, Mr. G. H. Paulin, A. R. S. A., and Mr. H. Tyson Smith have been elected associates of the Royal Society of British Sculptors.
Mr. William Hunter, Mr. Alexander Jamieson and Mr. William T. Wood, R. W. S., have been elected members of the Royal Institute of Oil Painters.
An enquiry has been held, on behalf of the Council of the British Archælogical Association, by Miss Rose Graham, M. A., F. S. A., and Mr. P. M. Johnston, F. S. A., F. R. I. B. A., into the merits of a claim that a small chapel or cell at Luton Parish Church, about 8 feet long and 3 feet wide, was a “Pyx” chapel,
or connected with a receptacle for the reservation of the Sacrament The referees find the claim to be unfounded, the term “Pyx” having nothing to do
with the Sacrament, but with the current coinage of the realm, as at Westminster Abbey, being, moreover, unknown before the Reformation. The carvings which were supposed to confirm the sacramental idea are also found to be a punning allusion to part of the name of Vicar Barnard, a former incumbent.
Penryn is to have an all-concrete road, the local authority having decided to adopt this form of construction in Commercial Street, to withstand the damage caused by the spring tides which, normally, flood the main roads each year. The cost will be £2, 800.