Building the Skyline: The Birth and Growth of Manhattan's Skyscrapers
Carmen Devlin reviews a book by Elias Renner about how New York City's skyline came to be
Elias Renner's Building the Skyline walks readers through a close history of New York City, pulling together geology, the historical record, economic reasoning and a great deal of data to account for why clusters of business took root where they did, and how choices made early on by firms and workers left their imprint on today's skyline. Renner splits the book into two clearly separate halves. The opening half is largely history, tracing the city's founding and its expansion from 1609 to 1900; the closing half turns mainly to the twentieth century, gathering chapters that each comment on some facet of the city's development. The voice and structure shift a little between the two, since the later chapters lean on material drawn from Renner's own research articles.
The opening chapter begins with what Renner calls a 'helicopter time-machine' journey, an absorbing description of how the New York terrain might have looked from overhead in 1609. He then leads the reader beneath the streets, mapping where rock and water sit under the topsoil, before bringing everyone back to ground level. His affection for the place is unmistakable as he recounts assorted curiosities, among them where the early nineteenth-century mayor DeWitt Clinton once kept his New York home, along with several of the myths that have gathered around the city.
The following two chapters carry the reader up to the Civil War (1861-1865). Chapter two dwells on how land first came to be developed and on the grid plan brought in during 1811, whereas chapter three examines the ways land was put to use in the years leading up to the war. Both are well researched and rich in detail, and together they prepare the ground for the economic argument the book builds later on. One assertion I wished Renner had pursued further is his contention that the tenements* already standing in some districts kept skyscrapers away, since no builder of tall towers would have wished to undertake the 'slum clearance' that would first be needed. Yet elsewhere he holds that how deep the bedrock** lay set no genuine limit on developers, foundations being only a slender share of a project's total cost. Why clearing slums should count as a barrier when pricier foundations do not is not, at first sight, easy to see.
Chapter four shifts to immigration and to where neighbourhoods and tenements were situated in the final decades of the nineteenth century. Renner singles out three principal immigrant districts and looks at where each sat in relation to the amenities close at hand. In the main these districts took up the least valuable ground, hemmed in between the industry strung along the waterfront and the well-to-do streets that fringed Central Park.
The book's second half opens by weighing the economics that decide how tall a skyscraper ends up being. Renner, in chapter five, separates out three ideas of height. Engineering height is the greatest a structure can rise to in safety given the technology of the day; economic height is whatever height serves society most efficiently; and developer height is the figure a developer settles on while trying to wring the most from the money invested.
That same chapter also offers an engaging look at the technical breakthroughs behind the rise of skyscrapers. Frames of iron and steel, for one, removed the need for thick load-bearing walls, which both opened up usable floor area and let in far more windows and daylight. Chapter six then sets out figures on the height of buildings across the twentieth century and turns to regression analysis to forecast construction. Pitched though it is at a gentler technical level than the research paper it grows out of, it is still likely to strike the ordinary reader as rather too technical.
Chapter seven confronts the so-called bedrock myth: the belief that no skyscrapers went up in the corridor separating Downtown from Midtown because the bedrock there lies too deep below the surface. Renner's reply is that deeper bedrock certainly raises the price of foundations, yet that price was neither ruinously steep nor sizeable when weighed against the total cost of erecting the skyscraper. The portion I most enjoyed was his account of the way foundations really get put in. He sets out how caissons let workers dig steadily downward across long stretches, often well beneath the water table, until they reach bedrock. His careful technical narrative covers not merely how a caisson works but the perils that go with it. Resting though it does on empirical research papers, the chapter still makes for a fairly easy read.
Chapters eight and nine dwell on the coming of Midtown and the construction surge of the 1920s. Chapter eight runs to long stretches of urban economic theory that anyone whose chief concern is New York itself might treat as a detour, though those passages would suit undergraduates taking up the economics of cities rather well. In the chapter after it, Renner sets the two explanations most often advanced for the 1920s surge side by side, the first a mood of exuberance and the second the ready supply of finance. Testing each against the data, he judges that supply and demand explain much of what was put up in that decade; cheap credit, to his mind, opened the door to the boom but was not the force chiefly behind it.
The book's last chapter draws on a further empirical paper of Renner's, one that puts a value on Manhattan land from the middle of the nineteenth century to the present. What is especially striking is the sheer amount of effort that produced these figures. As the chapter nears its close, Renner turns to whether tall buildings bring about high land values or merely follow from them, concluding that movements in land value can foretell the height of buildings still to come while the reverse cannot be shown. A closing epilogue rounds things off, with Renner considering how a changing climate will press on the city and laying out policy suggestions for the New York of the future.
* tenements: apartment buildings, especially ones that are overcrowded or in poor condition ** bedrock: the solid rock lying beneath the surface soil
