Structural engineering
Building science
A significant achievement of the first industrial age was the emergence of building science, particularly the elastic theory of structures. With it, mathematical models could be used to predict structural performance with considerable accuracy, provided there was adequate quality control of the materials used. Although some elements of the elastic theory, such as the Swiss mathematician Leonhard Euler’s theory of column buckling (1757), were worked out earlier, the real development began with the English scientist Thomas Young’s modern definition of the modulus of elasticity in 1807. Louis Navier published the elastic theory of beams in 1826, and three methods of analyzing forces in trusses were devised by Squire Whipple, A. Ritter, and James Clerk Maxwell between 1847 and 1864. The concept of a statically determinate structure—that is, a structure whose forces could be determined from Newton’s laws of motion alone—was set forth by Otto Mohr in 1874, after having been used intuitively for perhaps 40 years. Most 19th-century structures were purposely designed and fabricated with pin joints to be statically determinate; it was not until the 20th century that statically indeterminate structures became readily solvable. The elastic theory formed the basis of structural analysis until World War II, when bomb-damaged buildings were observed to behave in unpredicted ways and the underlying assumptions of the theory were found to require modification.
The coming of the industrial age also marked a major change in the role of the architect. The artist-architects of the Renaissance had the twin patrons of church and state upon whom they could depend for commissions. In the rising industrial democracies the market for large-scale buildings worthy of an architect’s attention widened, and the different users asked for a bewildering range of new building types. The response of the architect was to develop the new role of licensed professional on the model of professions such as law and medicine. In addition, with the coming of building science, there was a further division of labour in the design process; structural engineering appeared as a separate discipline specializing in the application of mathematical models in building. One of the first buildings for which the architect and engineer were separate persons was the Granary (1811) in Paris. Societies representing the building design professions were founded, including the Institution of Civil Engineers (1818) and the Royal Institute of British Architects (1834), both in London, and the American Institute of Architects (1857). Official government licensing of architects and engineers, a goal of these societies, was not realized until much later, beginning with the Illinois Architects Act of 1897. Concurrent with the rise of professionalism was the development of government regulation, which took the form of detailed municipal and national building codes specifying both prescriptive and performance requirements for buildings.
Environmental control technologies began to develop dramatically in the first industrial age. The first major advance was the use of coal gas for lighting. Coal gas was first made in the 1690s by heating coal in the presence of water to yield methane, and in 1792 William Murdock developed the gas jet lighting fixture. The first large building to have gas lighting (from a small gas plant on the site) was James Watt’s foundry in Birmingham in 1803. The Gas Light and Coke Company was founded in London in 1812 as the first real public utility, producing coal gas as a part of the coking process in large central plants and distributing it through underground pipes to individual users; soon many major cities had gasworks and distribution networks. Gas was expensive, however, and was used mainly for lighting, not for heating or cooking; it also contained many impurities that produced undesirable products of combustion (particularly carbon soot) in occupied spaces. Relatively pure methane in the form of natural gas would not be available until the exploitation of large oil fields in the 20th century.
The stove and fireplace continued as the major sources of space heating throughout this period, but the development of the steam engine and its associated boilers led to a new technology in the form of steam heating. James Watt heated his own office with steam running through pipes as early as 1784. During the 19th century, systems of steam and later hot-water heating were gradually developed; these used coal-fired central boilers connected to networks of pipes that distributed the heated fluid to cast-iron radiators and returned it to the boiler for reheating. Steam heat was a major improvement over stoves and fireplaces because all combustion products were eliminated from occupied spaces, but heat sources were still localized at the radiators.
Plumbing and sanitation systems in buildings advanced rapidly in this period. Public water-distribution systems were the essential element; the first large-scale example of a mechanically pressurized water-supply system was the great array of waterwheels installed by Louis XIV at Marley on the Marne River in France to pump water for the fountains at Versailles, about 18 kilometres (10 miles) away. The widespread use of cast-iron pipes in the late 18th century made higher pressures possible, and they were used by Napoleon in the first steam-powered municipal water supply for a section of Paris in 1812. Gravity-powered underground drainage systems were installed along with water-distribution networks in most large cities of the industrial world during the 19th century; sewage-treatment plants were introduced in the 1860s. Permanent plumbing fixtures appeared in buildings with water supply and drainage, replacing portable basins, buckets, and chamber pots. Joseph Bramah invented the metal valve-type water closet as early as 1778, and other early lavatories, sinks, and bathtubs were of metal also; lead, copper, and zinc were all tried. The metal fixtures proved difficult to clean, however, and in England during the 1870s Thomas Twyford developed the first large one-piece ceramic lavatories as well as the ceramic washdown water closet. At first these ceramic fixtures were very expensive, but their prices declined until they became standard, and their forms remain largely unchanged today. The bathtub proved to be too large for brittle ceramic construction, and the porcelain-enamel cast-iron tub was devised about 1870; the double-shell built-in type still common today appeared about 1915.
The second industrial age
If the first industrial age was one of iron and steam, the second industrial age, which began in about 1880, could be called one of steel and electricity. Mass production of this new material and of this new form of energy also transformed building technology. Steel was first made in large quantities for railroad rails. Rolling of steel rails (which was adapted from wrought-iron rolling technology) and other shapes such as angles and channels began about 1870; it made a much tougher, less brittle metal. Steel was chosen as the principal building material for two structures built for the Paris Exposition of 1889: the Eiffel Tower and the Gallery of Machines. Gustave Eiffel’s tower was 300 metres (1,000 feet) high, and its familiar parabolic curved form has become a symbol of Paris itself; its height was not exceeded until the topping off of the 318.8-metre- (1,046-foot-) tall Chrysler Building in New York City in 1929. The Gallery of Machines was designed by the architect C.-L.-F. Dutert and the engineer Victor Contamin with great three-hinged arches spanning 114 metres (380 feet) and extending more than 420 metres (1,400 feet). Its glass-enclosed clear span area of 48,727 square metres (536,000 square feet) has never been equaled; in fact, it was so large that no regular use for it could be found after the exposition closed, and this magnificent building was demolished in 1910.