Author: David B. Williams

America’s Building Stone – Chapter 6

Go to any city across the country and you will find one building stone in all of them: Salem Limestone from Indiana. People pray, have babies, get drivers licenses, and file for divorce in structures made from this 330-million-year old buff rock. Salem was also the first stone that many people encountered when they entered the United States; the administration building at Ellis Island was completed in 1900 with Salem Limestone trimming the red brick.

As with most building stones, use of Salem started locally with workers hauling blocks eight miles for the foundation and window sills of a county courthouse in 1819. The first quarry opened eight years later but little stone made it outside Indiana until the railroad reached Bedford and Bloomington in 1853.

The big break for Salem quarriers came in 1871 when Chicago burned to the ground. Within a few years, Indiana quarrymen had set up shop to promote their stone. One promoter wrote, “This purity insures absolute integrity on exposures to the fumes of coal, while the perfect elasticity and flexibility of the mass render it invulnerable to the forces of cold and heat, air and moisture.” Others claimed that the stone cleaned itself and that it had withstood the ice age “scarcely changed in any part.”

The Salem soon became the stone of Chicago. In 1889 William Vanderbilt ordered 25 carloads for a mansion on Fifth Avenue and his august imprimatur spurred others to follow. Within a decade Salem dominated markets in Philadelphia, New York City, Boston, Cincinnati, Kansas City, and Cedar Rapids.

Several aspects of Salem Limestone combined to make everyone from Odd Fellows to opera fans incorporate the stone in their structures. Stone masons can cut, plane, flute, and carve the Salem easily and in all directions and once shaped, Salem hardens over time. It splits evenly, and in any direction. When rock had to bear the weight of a building, Salem excelled because of its low compressibility. When stone became a skin hanging on a steel skeleton, Salem remained popular because of its ease in cutting.

Changes in architectural fashions also helped sell Salem Limestone. In the last quarter of the 19th century, architects turned away from the dark, somber stones, such as brownstone, that dominated cities in the eastern United States. Salem Limestone also benefited from the growth of coal-fired plants, because Salem stones did not disintegrate under attack by coal-generated pollution like other limestones. (As geologist David Dale Owen wrote in 1838, Salem Limestone “would imbibe less water.”) By 1928, the peak year of production, Indiana quarries provided 70% of all exterior building stone used in the United States.

Salem Limestone quarries are still active, shipping rock as far as Japan and Turkey. In the United States, Salem-clad buildings occur in all 50 states, and include 27 state capitols, 750 post offices, and 200-plus courthouses. It is the most commonly used building stone in the country.

The Clam That Changed the World – Chapter 5

Hardly anyone thinks that clams changed the world. Most are benign, industrious critters toiling away in the sand or resting quietly in the sea. If we do consider them, it’s mostly because many are edible and some produce valuable, nacre-coated irritants worn as fashion. Perhaps the most famous bivalve in the world is the one that supports Venus in Botticelli’s legendary painting, The Birth of Venus. Botticelli depicts the Roman Goddess of beauty and love using the shell as a mode of transport as she arrives on land, blown by the winds. Although unrealistic as a way to travel, Botticelli’s shell does fit the classic image of a bivalve, something trod under foot.

Castillo de San Marcos, courtesy of National Park Service

Thus some find it odd that a bivalve, in particular a much smaller clam than the one that carried the lovely Venus, was seminal to the early history of colonization of North America. Carolina governor James Moore was the first to discover the power of the clam when he lay siege to the Spanish town of St. Augustine, Florida, in 1702. Moore attacked St. Augustine with 800 men, which forced all of the town’s residents into their recently completed fort, known as Castillo de San Marcos.

For six weeks, Moore bombarded the Castillo, but with no luck. Cannonballs either bounced off of or stuck in the fort without breaking the walls. What was the miraculous building material? It was an unusual variety of limestone called coquina (Spanish for “little shell”), which outcrops along the northern Florida coast. It formed 110,000 years ago as billions of bivalves accumulated on beaches. By far the most abundant bivalve is the coquina clam, Donax variabilis, the clam that changed the world.

Moore eventually abandoned his nefarious plans and retreated back to Carolina. Thirty years later the English tried once more to take St. Augustine. Again they failed because of the coquina, leading one British soldier to express “[it] will not splinter but will give way to a cannon ball as though you would stick a knife into cheese.” Without the clam, one can argue that the English would have succeeded in invading St. Augustine, driven the Spanish out of Florida, and who knows how the world would have turned out.

But because of the clam, no armed force ever took St. Augustine. The Castillo still stands, a wonderful tribute to the power of stone to influence architecture, history, and politics.