Stories in Stone

by David B. Williams

  When the new residents began to move into these neighborhoods, they began to repair and restore the buildings. “People didn’t have the money they have now, so there was less attention to detail. In many cases, owners simply removed or shaved off features, in particular around windows,” said Alex Barrett, an architect who focuses on brownstone restoration in Brooklyn.9 Where once a prominent sill and ornate molding and brackets surrounded a window with distinction, plain windows now punctuated buildings with flaccid monotony. Owners also lopped off stoops, abandoning the original entryways like forgotten lovers.

  South Portland Avenue in Brooklyn.

  To stave off erosion of the stone, brownstoners, as the new immigrants dubbed and still dub themselves, also painted brownstone facades. In a second mistake from the 1960s, many brownstoners used nonbreathable paint, which trapped moisture and exacerbated stone spalling. Other brownstoners patched the weakened stone with stucco. Often, however, they failed to match the colors of stucco and stone, leaving the building looking like a teenager’s blotchy face. With more experience and money, later owners began to stucco the entire building, and it is these more modern restorations that rankle brownstone purists.

  “We recently restored a five-story building and spent seventy-five thousand dollars, which was a good price. We could have paid much less or much, much more. It took two to four guys working full time four months to complete it,” said Barrett. First, restorers jackhammered off the old stucco to get down to the original stone. They then applied a gray cement mortar mixed with coarse aggregate to form a base, or scratch coat. Barrett’s restorers hand molded all of the scroll work around the new windows using simple trowels. They rebuilt the steps by hand with stucco. On the finish stucco coat, they applied an aggregate-free cement mortar with a custom-created mix of colored sand.

  The artistry of a high-quality restoration such as the one on Barrett’s row house bestows a dignity that harkens back to the glory days of the brownstone, when owning one meant that a person had achieved a certain level in society. The fancy detailing around the windows and doors gives the building elegance, style, and depth. Barrett’s attention to detail results from his interests and concerns about history and the importance of brownstone to the development of New York. But I miss the imperfections of true brownstone. Most restorers, at least the high-end ones, do such a good job that the buildings lack character. The lines are too straight, the stucco too homogenous, the color too even. While stucco restoration corrects the fatal flaws of the past, the buildings lose their soul. The great row houses of modern Brooklyn are no longer brownstones but “brownstuccos.” They could fit right in in Santa Fe, stucco capital of the world.

  What I like best about brownstone is its geologic essence. When you look closely, you can see that the individual sand grains vary in size from mote to pebble, and in color from reddish to deep mocha. Some bedding planes are thick, some are wavy, and some are not visible because the builder placed the stone with the bedding plane face out, which tends to make the blocks look like wood grain. The erosion differs, depending on resistance and aspect. I found one building with a pair of dragon faces carved out of brownstone below the front porch. One retained its detail while the other had worn away to a ghost of its original fierceness. This heterogeneity reflects the original, complex depositional environment of the stone 200 million years ago.

  Most people do not encounter geologic phenomena on a daily basis. You may read about distant volcanoes, earthquakes, and tsunamis in the news but with brownstone you can see the same processes that wore down the Appalachian Mountains and carved the Grand Canyon. You can see how water and ice infiltrate and ferret out the weakest links in a rock and slowly reduce it to its constituent grains. A solid in geologic time is not truly a solid, and it will surrender to an overriding principle of nature—gravity; what goes up must come down, even if it takes millions of years or in the case of the hapless brownstones, decades.

  The basic geologic story of brownstone is simple and appealing. Go back 200 million years. Streams wash into a valley and deposit layer upon layer of sand and silt. Dinosaurs plod through the wet sediments leaving behind thousands of tracks. Sediments and tracks harden into sandstone. To understand why dinosaurs inhabited that valley, why quarries occur where they do, and why brownstone was a good building stone, however, requires adding a few more details.

  The valley where the dinosaurs roamed sat in the middle of the supercontinent of Pangaea, which like a giant puzzle, consisted of many smaller pieces of land. The northern portion, called Laurasia, included Siberia, Europe, and North America. Antarctica,Africa, South America, India, and Australia, collectively known as Gondwana, formed the south part of Pangaea and extended down to the South Pole. All was not right, however. As that great geologist Bob Dylan sang, “He not busy being born is busy dying,” and Pangaea began to break up.

  At least fifteen rift valleys, or basins, opened as North America,Africa, and South America pulled away from one another. The individual basins stretched from Alabama to the Bay of Fundy. Streams from adjacent hills and mountains began to carry sand and silt into the basins, including one where the Connecticut River now flows, from about modern-day Amherst, Massachusetts, to New Haven, Connecticut. Geologists call this lowland either the Connecticut River valley or the Hartford Basin.

  Between about 220 and 195 million years ago, this valley lay about ten to fifteen degrees north of the equator, roughly the same latitude as present-day El Salvador. Dry and warm with an ecosystem of ferns, cycads, and conifers, the lowland received less than twenty inches of rain per year, mostly as seasonal monsoons. A variety of small dinosaurs, about six feet tall and shorter, ten-foot-long amphibians, and fish-eating crocodilelike animals inhabited the valley.

  And then, as the continents continued to pull apart, Earth’s crust thinned and the Hartford Basin ripped open, like an overstuffed sausage. Black lava spread from swarms of fissures in Connecticut and all of the rift valleys that stretched for a thousand miles along the eastern margin of North America. With a consistency of ketchup, the basalt flowed thousands of yards per day. In addition to wreaking havoc on the landscape, the viscous basalt spewed out trillions of tons of sulfur dioxide and carbon dioxide, generally making the planet an unpleasant place for any species that liked clean air.

  Geologists speculate that this worldwide flood of basalts may have contributed to a mass extinction of 50 percent of planetary life, including a diverse group of carnivores and herbivores, generally bigger and badder than dinosaurs who lived at the time. With their competitors out of the way, dinosaurs, which had first evolved about 30 million years earlier, reacted quickly and doubled in size. They also began to evolve into the myriad species that dominated Earth for the next 140 million years. Within twenty-five thousand years of the extinction, new forms had emerged including Anchisaurus, a long-necked herbivore, and twenty-foot-long predators such as the double-crested Dilophosaurus, one of the stars of Jurassic Park.10 They had taken over from slim, three-foot-long plant eaters and similarly sized meat eaters. Nowhere on the East Coast is this record of dinosaur ascendancy better recorded than in the fifteen thousand feet of sediments that accumulated in the Connecticut River valley.

  Of all the rock that formed in the valley, the thickest,youngest, and most important to the brownstone story is the Portland Formation. Named for its main point of origin—the town of Portland, Connecticut—it is the rock unit that provided the building blocks for most of the brownstone row houses of New York and Boston. The stone formed very rapidly, in just a few million years, as streams carried sediments out of the surrounding highlands and into a valley of lakes, floodplains, and river channels.

  The warm and well-watered valley was ideal habitat for dinosaurs. As they tromped around in the moist mud and sand along the valley’s streams and lakes, the great and the small left behind thousands and thousands of footprints, which remained intact as the mud hardened to rock. These tracks are one of the coolest and also mo
st geologically important aspects of the brownstone. Because fossilized footprints record a specific moment in time in the life of an animal, they eventually helped paleontologists revolutionize our understanding of dinosaurs.

  * * *

  In 1802 a lad named Pliny Moody was working his family’s field in South Hadley, Massachusetts, when his plow thumped against a block of brown sandstone. Clearing away the soil, Moody discovered four raised tracks crossing the flat slab. Each four-inch-long track had three toes and looked like it was made by a bird. Since the slab was of no use in the field,Moody’s family decided to use it as a doorstep, where it remained for several years until a local doctor, Elihu Dwight, purchased the curious rock. Dwight nicknamed the tracks’ maker Noah’s Raven, and showed them to Amherst College natural history professor Edward Hitchcock, who also thought that birds had made the tracks.11

  The Noah’s Raven slab is now on display in an honored spot in the main collection of tracks at the Amherst College Museum of Natural History. Three feet by two feet by two inches thick, the reddish slab tapers to twelve inches wide at the bottom, where the top two inches of a toe are visible. Three other tracks run in a line up the slab, clearly showing where a dinosaur walked across the wet sand. The tracks are darker and raised slightly above the surrounding rock. They aren’t actually an impression but a positive cast of the original track. Dinosaur tracks form when an animal steps in moist, firm sediment, which subsequently dries and hardens. New sediment then fills in the track, creating a cast, as well as preserving the original. Geologists generally refer to both the cast and the original as tracks.

  Hitchcock, who acquired the slab from Dwight, was close to correct about what walked around in the mud of the ancient valley. A dinosaur, the progenitor of birds, made the Noah’s Raven tracks about 200 million years ago. It stood about thirty-six inches tall and walked on two feet in a pigeon-toed manner. Other tracks from this dinosaur species indicate that they could have walked on all fours, occasionally dragged their tails, rested with their breast and rump on the ground, and traveled in family groups. They also fidgeted, or at least multiple prints in the same locality indicate that they stomped or patted their feet when resting. The same type of tracks have been found across eastern North America, in South Africa and Poland, and on the Colorado Plateau. Paleontologists call the track maker Anomoepus, meaning “unlike foot.”12

  Noah’s Raven is only one part of Amherst's collection of twenty thousand tracks and casts. Most of them came from the Connecticut River valley, either from the Portland Formation, including the Noah’s Raven slab, or equivalent rocks in other parts of the valley in Massachusetts. The collection, the world’s largest, was assembled by Edward Hitchcock between 1836 and 1864 and now resides in a beautiful new museum on the Amherst campus.

  “Hitchcock was the preeminent geologist in America,” said Steve Sauter, coordinator of education at the Amherst museum.13 And yet Hitchcock never conceded that the Noah’s Raven tracks were made by a dinosaur and therefore were the first evidence of dinosaurs found in America. (British naturalist Richard Owen coined the term dinosaur in 1841 and by the 1850s most geologists and naturalists knew dinosaurs to be a widespread and diverse group.) “Hitchcock could never accept that God created monstrous beasts like dinosaurs,” said Sauter. “He always thought that birds made the tracks.”

  Hitchcock was a bizarre mixture of scientist, puritan, hypochondriac, and country bumpkin. Born in 1793 in Deerfield, Massachusetts, he only attended six winter terms at Deerfield Academy, which at the time was a K–12 public school. He didn’t go to Harvard or Yale because he got it into his head that he was too sickly to attend. Other people in town helped look after his intellectual interests, however, lending him books on Latin and Greek and talking to him about subjects such as military tactics. He became a Congregational minister but with minimal training. He didn’t drink alcohol, ate no meat, and subsisted on a cornmeal gruel made with tepid water.

  Hitchcock had an intense interest in science. He started to conduct his own experiments and reported his findings to professional scientists such as Benjamin Silliman, Yale’s influential professor of chemistry, mineralogy, and geology. Word got out about the scientifically inclined minister, and in 1825 Amherst offered him a job teaching theology and science. Hitchcock knew he knew theology but was unsure about science, so he appealed to Silliman for help. He spent several months learning to teach science from Silliman and returned to become Amherst’s professor of chemistry and natural history. He remained at Amherst until his death in 1864.

  Ten years after starting at Amherst, Hitchcock’s life changed when he received a letter from a local doctor, James Deane. Deane’s letter described “the tracks of turkeys in relief” from a slab of sandstone about to be used as a sidewalk in Greenfield, Massachusetts.14 Hitchcock ignored the letter until Deane finally sent plaster casts of the tracks. Now convinced that they were tracks, Hitchcock traveled to Greenfield to see the slab. Within a year he had found more tracks in sidewalks in Northampton and Deerfield, as well as in several quarries. He had also seen the Noah’s Raven slab and collected enough additional tracks to publish America’s first scientific paper on fossil tracks. He called the nascent field ornithichnology, the study of stony bird tracks.15

  Hitchcock’s paper described seven species of track makers. The casts and impressions ranged in size from the four-inch-long Noah’s Raven to the massive Ornithichnites giganteus (gigantic stony bird tracks) with fifteen-inch-long feet and a six-foot-long stride. Tracks of several different species walking in different directions covered one slab. Another showed one animal leaving over ten tracks in a steady line and most were so distinct Hitchcock could determine the left and right foot. He concluded that “they could not have been made by any other known biped, except birds.”

  Smitten with tracks, Hitchcock started collecting them himself. He always wore his black suit and tie when out in the field, although often he would sneak home late at night because he recognized that digging and transporting tracks was “not comporting with the dignity of a professor.”16 He even found and made a cast of tracks from a sidewalk on Greenwich Street in Manhattan. Hitchcock later wrote that casting the Greenwich tracks almost landed him in the local asylum: A former student saved him when she testified that he was “no more deranged than such men usually are.”17

  His favorite track slab came from the Portland brownstone quarry. It had been used for decades as a sidewalk, with the nontrack side facing up, until yet another local doctor heard of Hitchcock’s interest in tracks and remembered he had seen unusual markings on the slab when it had been laid in place. (I wonder what all the sick people were doing while these doctors were searching for tracks.) Called by Hitchcock the “gem of the Cabinet,” it shows mud cracks, worm tracings, and 54 beautifully preserved track casts of several species.18 By the time he died, Hitchcock had named 216 species from thirty-eight localities and published more than thirty reports, including his magnum opus, Ichnology of New England, which contained some of the first photographs taken of fossils.

  Hitchcock’s work took place at a critical time, when geologists were starting to refute the accepted dogma of the biblical stories of Adam and Eve, Noah’s flood, and God’s creation. In 1815 William Smith published the world’s first geological map, which showed the geology of England and Wales. Smith based his work on his observation that sedimentary strata contain fossils that occur in a definite, predictable sequence and that these layers could be correlated between locations. Combined with Nicolas Steno’s law of superposition, which states that older rocks lay under younger rocks, Smith’s work made geology into a three-dimensional science based on descriptive analysis instead of pure speculation.

  Edward Hitchcock’s “gem of the Cabinet,” catalog number 9/14.

  Fifteen years later, Charles Lyell published his seminal work, Principles of Geology, which argued that natural laws did not change over time, therefore modern geologic processes acted in the same way and at the s
ame rate as they had in the past. Lyell’s book helped establish that Earth was not created six thousand years ago but must be very old because geologic phenomena, such as erosion and deposition, occurred so slowly that vast expanses of time were necessary to produce the planet’s varied landscapes.

  A third great advance came from Swiss-born geologist Louis Agassiz, whose Étude sur les glaciers in 1840 established the importance of ice in sculpting landscape. Agassiz showed that a great and geologically recent ice age was responsible for ice sheets that carved valleys, shoved moraines, and carried erratic boulders. His work was another critical step in helping to dispel the myth that catastrophes (i.e., biblical deluges) were responsible for modern geologic features.

  Finally, with Charles Darwin’s On the Origin of Species, published in 1859, geology also started to address the great biological questions. Through careful observation, accumulation of data, and formation of testable theories, geologists of the nineteenth century opened major doors in understanding the history of Earth. Plants and animals evolved and went extinct. Landscapes changed, sometimes drastically, over time. Earth was a very old planet. These are the central themes that still drive geology.

  “It’s just stunning that all of this is coming together. That the science of geology was just exploding,” said Sauter. “Western travelers are bringing back all of these fossil specimens and animals, like dodo skeletons and moa skeletons in the Pacific. It’s all coinciding and all clashing with this biblical belief and there’s Hitchcock in the middle of this storm. And he is the first person to have the imagination to question the tracks. To ask, What kind of animals made these footprints? How could prints be made in stone? How old are these footprints? He essentially creates an entire new field of science.”