Fire and Stone

The recent and tragic fires around Los Angeles have prompted me to write about the connection between fire and stone. Vitruvius was one of the first to consider the connection. In his landmark De Architectura, or The Ten Books of Architecture, written sometime between 31 and 27 BCE, he wrote of travertine blocks. “They cannot be safeguarded against fire. As soon as they make contact with it, they crack apart and fall to pieces.” Instead he recommended the use of tuff.

Like the Greek philosophers Aristotle and Plato, Vitruvius considered that matter consisted of unique combinations of the elements water, earth, air, and fire, which gave an object, such as a stone, unique properties. Too much air and fire, according to Vitruvius, made travertine susceptible to breaking at high temperatures. Modern scientists point to the unequal amounts of extension and contraction along internal crystallographic axes in calcite for travertine’s poor performance in fires. Geologist Marie Jackson has found that tuff survives fire better than travertine because of its porous texture, which allows tuff to expand when heated with far less fracturing than travertine.

The problems caused by fire often drove building practices. In 1680, the General Court in Boston passed a resolution requiring slate roofs, after a fire destroyed 80 buildings and 70 warehouses. Others fire led to cities such as Boston, Seattle, and New York passing laws stipulating that new buildings be built with stone or brick. And James Flood’s brownstone mansion was the only building on Nob Hill to survive the fires that followed the 1907 San Francisco earthquake.

Former James Flood mansion, Nob Hill, San Francisco

The argument has also been made that Chicago’s Great Fire of 1871 helped make the Salem Limestone the most commonly used building stone in the country. Historians and promoters of Salem Limestone have written that the “buildings that suffered least from the fire were of limestone.” Newspaper accounts from the time, however, report that during the fire, limestone “seemed as though [it] actually burned like wood.” Builders were so prejudiced against the local stone, most of which came from nearby Joliet and Lemont, that in the first 30 days after the fire, most ordered brick, from as far away as Philadelphia.

Chicago Auditorium by Sullivan and Adler (copyright from Boston College professor Jeffery Howe)

The true qualities of the Salem—durability, accessibility, and ease of cutting—ultimately proved superior. By the mid 1880s, architects such as the high-profile firm of Sullivan and Adler had begun to use Salem regularly, most prominently on their Chicago Auditorium, built in 1887. Others followed, demand grew, limestone-laden trains bore north, and Salem buildings spread across the Windy City. By the mid-1890s, the Salem limestone was being shipped across the country, en route to staking its “most popular” claim.

The Getty Center (copyright David Williams)

Two months ago, another fire in Los Angeles made it into the news. This one threatened the Getty Museum. If the fire had engulfed the buildings, they would have put Vitruvius to the test. Travertine, and in fact, travertine from the same quarries that supplied Rome in Vitruvius’ time, clads the Getty’s buildings. Fortunately, fire fighters contained the blaze and no stone was harmed. I also suspect that fire fighting has improved a bit in 2,000 years.

Brownstone Tombstones

Continuing my theme of tombstones, I would like to turn to a singular grave marker in Middletown, Connecticut, just across the border from the old brownstone quarries in Portland. I believe this may be the only tombstone with dinosaur tracks on it. It honors Joseph Barrett, an M.D., though judging from the stone, he was equally as proud to be a botanist and geologist. Who wouldn’t?

Barrett was well known in the area for his passion for tracks. His obituary in the New York Times read “So deeply was he engaged in this work that he neglected his profession and became a monomaniac on the subject of bird tracks. He saw all manner of fossils in city walks which no other eyes were able to see, and in his peregrinations about the town would stop suddenly, look at a stone, bring out a sheet of wrapping paper and, laying it out on the walk, draw upon it whatever his fancy painted, write the place where the stone lay and date its discovery.” Oh, to be able to see those drawings!

Barrett also regularly supplied tracks to Edward Hitchcock, who taught at Amherst College and is considered the father of ichnology. Hitchcock never could admit that dinosaurs made the tracks; birds were the track makers.
When Barrett died, according to brownstone historian Alison Guinness, the local quarries donated two slabs of stone. You can find the facts on the smooth face. You can also see how brownstone weathers, peeling off layer by layer like sunburned skin. The back side, though, is the face to explore. Several three-toed tracks can be seen crossing at angles to each other. The most obvious one is just to the left of center, next to a round white lichen. Another one is a few inches down and to left. They have been designated as Grallator formosus and Brontozoum sillimanicum.

The back side of Barrett’s tombstone. Note the various tracks of three-toed dinosaurs.
The second slab, which the first sits on, has two tree casts. In addition, you can see where it says “The Testimony of the Rocks.” This book, written by Scottish geologist Hugh Miller and published the year after his death in 1857, is a curious combination of anti-evolution but supportive of a great age for the Earth.

Together these two slabs are certainly a wonderful tombstone testimony to the passion of a man for the stone and the fossils he loved.