Authors: David B. Williams
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
.
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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 most 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.
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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.”
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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.
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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.