At Home - Bill Bryson [121]
Concrete was one of the most exciting products of the nineteenth century. As a material, it had been around for a very long time—the great dome of the Pantheon in Rome is made of concrete; Salisbury Cathedral stands on concrete foundations—but the modern breakthrough for it came in 1824 when Joseph Aspdin, a humble bricklayer in Leeds, in the north of England, invented portland cement, so called to suggest that it was as attractive and durable as portland stone. Portland cement was vastly superior to any existing product. It even performed better in water than the Reverend James Parker’s Roman cement. How Aspdin invented his product has always been something of a mystery, because making it required certain precisely measured steps—namely, pulverizing limestone to a particular degree of fineness, mixing it with clay of a specific moistness, and baking the whole at temperatures much higher than would be found in a normal lime kiln. None of this was ever going to be hit upon by chance. What gave Aspdin the hunch to alter the constituents as he did and then to conclude that they would make a product that would set harder and smoother if heated to an extreme degree is a puzzle that cannot be answered, but somehow he did it and it made him rich.
For years, Edison was captivated by concrete’s possibilities, and around the turn of the century he decided to act on the impulse in a big way. He formed the Edison Portland Cement Company and built a huge plant near Stewartsville, New Jersey. By 1907, Edison was the fifth-biggest cement producer in the world. His researchers patented more than four dozen improved ways of making quality cement in bulk. Edison cement built Yankee Stadium and the world’s first stretch of concrete highway, but his abiding dream was to fill the world with concrete houses.
The plan was to make a mold of a complete house into which concrete could be poured in a continuous flow, forming not just walls and floors but every interior structure—baths, toilets, sinks, cabinets, doorjambs, even picture frames. Apart from a few odds and ends like doors and light switches, everything would be made of concrete. The walls could even be tinted, Edison suggested, to make painting forever unnecessary. A four-man team could build a new house every two days, he calculated. Edison expected his concrete houses to sell for $1,200, about a third of the cost of a conventional home of the same size.
It was a wild and ultimately unrealizable dream. The technical problems were overwhelming. The molds, which were of course the size of the house itself, were ridiculously cumbersome and complex, but the real problem was filling them smoothly. Concrete is a mixture of cement, water, and aggregates—that is, gravel and small stones—and it is in the nature of aggregates to want to sink. The challenge for Edison’s engineers was to formulate a mixture liquid enough to flow into every corner of every mold, but thick enough to hold its aggregates in suspension in defiance of gravity, while hardening to a smooth, uniform consistency of sufficient quality to persuade people that they were purchasing a home and not a bunker. It proved an impossible ambition. Even if all else went well, the engineers calculated, the house would weigh 450,000 pounds, causing all manner of ongoing structural strains.
All the technical challenges, plus problems of oversupply generally within the industry (which Edison’s huge plant did much to aggravate), guaranteed that Edison would always struggle to make money on the enterprise. Cement making was a difficult business anyway because it was so seasonal. But Edison pressed on and designed a range of concrete furnishings—bureaus, cupboards, chairs,