A very great deal is known concerning the strength of bricks. In addition to the innumerable experiments carried out by public bodies, we have the results of painstaking investigation by professors in universities and colleges, and the results carried out for and published by brickmakers themselves. Yet another large series of results have been published from time to time by professional journals, and it is, indeed, to these that we must look (at any rate in Britain) for anything like detailed work. The “Minutes of Proceedings of the Institution of Civil Engineers,” the “Transactions of the Royal Institute of British Architects,” the “Proceedings” of several allied provincial architectural societies, the “Builder,” the “British Clayworker,” builders’ “Price Books,” and several engineering “Handbooks,” have all contributed to our knowledge in regard to the strength of bricks. Of works consecrated entirely to the subject there are none--applied to British materials; but we have that excellent text-book by Professor Unwin, F.R.S., “The Testing of Materials of Construction,” and the important work by Mr. David Kirkaldy, both of the greatest possible value as being the results, largely, of original work. The experiments of recent years have been made almost exclusively by Mr. David Kirkaldy at his works in Southwark; by Professor W. C. Unwin at the Central Institution of the City and Guilds of London Institute; and by the Yorkshire College, Leeds. With such a wealth of information a whole treatise might profitably be written, but it will be understood that in a small work like the present we can only give a comparatively few results, prefaced by observations to impart a general idea.