Levees are used in engineering.......maybe i am wrong about that.......................Gregory H......from NYC.........in the movie.............................defected the other way...............Wash DC............American ambassadors in Moscow........the Kennedy Center............RFK stadium....both in Wash DC.............named for a famous American political family........from Massachusetts........like Mass ave..........................Embassy row .......here in DC....truncated......in 2025, August

Cutter's Way

CLARA JEFFERY

 SEP 8, 1995 12 AM

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Upstream from Georgetown on the Virginia side of the Potomac stand wooded cliffs bearing scars from the past. The scars are all that remain of the once flourishing bluestone quarries. The stone in these cliffs is actually gneiss, a coarse-grained rock like granite, but it is called bluestone from its blue-gray color. It served as building material for many of Washington's most important structures.”

Charles B. Grunwell penned these words in 1966 for the Washington Star Sunday Magazine, and they hold the key to the mystery of the Potomac's submerged iron boilers. Grunwell had firsthand knowledge of the cliffs and their scars—the broken and pocked rock, the shoreline littered with docking rings. His grandfather, Gilbert Vanderwerken, founded the Potomac Blue Stone Co. about the time of the Civil War. As a child during the 1890s, Grunwell watched stonecutters blast and chisel the rock, then load it onto scows that were pushed down the river by tugboat.

“The first step was to blast the rock out of the cliff. To do this, a scow with a steam boiler aboard anchored beside the river bank. From it a lengthy steam pipe extended to a drill hammer,” wrote Grunwell. “When the hole was drilled, the overseer filled it with blasting powder. He next inserted a cap into the end of the last charge and attached a fuse. Shouting at the top of his voice, "Fire in the hole!' he lit the fuse and ran for cover, with all the workmen following him. The blast that shortly followed shook the earth and was heard for miles around. Hundreds of tons of rock were torn from the cliff and hurled rumbling down into the quarry yard.”

Georgetown University's Healy Hall, St. Patrick's Church, the Hains Point sea wall, and St. Elizabeths Hospital were all built with Potomac bluestone, and rubble from the blasts was hauled to a stone crusher on Georgetown's waterfront, pulverized, and used as the foundation for local roads.

By the turn of the 20th century, the cutters had dynamited the cliffs back from the river, and it was becoming increasingly difficult and expensive to quarry rock from the Virginia palisades. So, in 1905, after the death of Vanderwerken, his daughters sold the Potomac Blue Stone Co. to the Columbia Sand and Gravel Company.