For a visit to Boston's Prudential Tower Skywalk last fall, James W. Skehan, SJ, brought along a thick stack of papers: the corrected galleys of his upcoming 400-page Roadside Geology of Massachusetts. The volume, published last month by Mountain Press, is part of a series that will include Connecticut and Rhode Island, he hopes -- "if I can get some funding . . . and the vitamins hold out." Skehan, now 77, is contemplating retirement from his post as director of Weston Observatory to make more time for writing. This trip downtown was to serve as a dry run for a tour he is organizing for the Geological Society of America's annual meeting, in Boston next fall.

"All those islands out there are drumlins," he said, pointing a beefy and well-weathered hand beyond the financial district's pristine skyscrapers toward the harbor islands. Skehan bears more than a passing resemblance to the comedian Jonathan Winters, although his humor is kinder: "A hill of a lot of till," he'd joked when asked to define drumlin. As the glaciers receded, he went on to explain, they sometimes deposited huge mounds of unsorted material called till -- clay mixed with gravel and stones -- which often settled in the shape of a football bisected lengthwise. Unprotected, the outer islands -- "the Brewsters and the Graves and so forth" -- were "washed clean of the glacial deposits, so they are bedrock," he said. "But you see all those islands in the harbor? All drumlins. Those islands were left here about 150,000 years ago."

Fr. Skehan, a.k.a. Rocky, pulled out a booklet he'd written in 1976 called Puddingstone, Drumlins, and Ancient Volcanoes. He opened it to a map of Boston as it appeared when the first English settlers arrived in 1630, superimposed on a modern-day street map. "See Washington Street?" he asked, turning a few degrees to the east and pointing down to the swarming maze below us. "By Boston City Hospital?" The original peninsula on which the city was founded was tiny -- barely a third of the current downtown landmass -- and was reached by a long, slender neck along what is now Washington Street: "Just 150 feet wide in some places," Skehan noted. "Originally Boston had three hills -- Beacon Hill, Pemberton Hill, and . . . " He drew a blank, then shrugged. "Anyway, they called it the Trimountain, that's where you get Tremont Street. The settlers planed down all but Beacon Hill and used the material to fill in the harbor.

"The early geologists," he said with apparent delight, "thought Beacon Hill was a drumlin. But that's because they weren't paying any attention to history." Pointing northwest out the window, he located Charles Street along the base of Beacon Hill. "That would be Acorn Street, right about there, just to the right of that white tower. That's about where William Blaxton was dickering with Governor Winthrop for water rights." Blaxton, the first Englishman to settle on the peninsula, later invited the Massachusetts Bay Company over from Charlestown when its water supply went bad. "The best water was located on the north side of Beacon Hill," Skehan continued, pointing toward Spring Lane, just off Washington Mall, where the first town well was dug. "There was water all over this hill," he said. If the geologists had read their history, they would never have called Beacon Hill a drumlin, because drumlins are dry.

Skehan went into lecture mode: "Basically, you take a quart jar, put pebbles in there, and then pour water in. Pebbles and sand and things like that will contain a lot of water, so you can pour the water out of the sand and gravel. Now suppose you fill it with sand and gravel and clay -- all mixed together. The clay is impervious. It's too fine-grained, so it will clog up the system. You don't get water out of a drumlin." He pulled out another diagram -- this one a cross-section of Beacon Hill, sliced along its north-south axis and stripped of the State House's golden dome and the crust of houses and lanes and sidewalks that form its human skin. He held the diagram parallel to the hill and interpreted: "On top, this is till. However, beneath the till there are these slabs of sand and gravel that were frozen and then pushed by the glacier, imbricated like shingle blocks, and these contain abundant water. But the early geologists were fooled by the shape of the hill and the till on the top." During digging for the Boston Common garage, developers expected a dry excavation, "but they found a tremendous abundance of water, which they didn't want. They lost their shirts."

Fr. Skehan had arranged a tour of four dioramas in the lobby of New England Financial -- the old New England Life building -- for later that morning, so we hustled a few blocks down Boylston Street. Passing the Boston Public Library, he paused to admire it: "Medfield granite. See that pink cast? It's distinctive. Lovely stuff." As we walked, he described another book he'd just written, Praying with Teilhard (St. Mary's Press, January 2001), meditations on the life and thought of his fellow Jesuit, the paleontologist Teilhard de Chardin.

When we reached the New England Life building Fr. Skehan's maroon-and-gold Boston College scarf and his safari hat and vest must have stood out, for the security guard immediately identified him by name and phoned the archivist down to meet us. Before long, Fr. Skehan was chatting pleasantly about the geological subtext of a diorama depicting the Reverend Blaxton negotiating water rights with Governor Winthrop. As we left the building he gestured toward the foyer's stonework. "This is Italian, from the north of Italy . . . I should know where . . . " He shook his head.

Back on Boylston Street, he regained his stride. Then, spotting something on the ground, he brightened and stopped short: "You know where this is from?" he asked, gesturing toward the sidewalk. "I think this is Deer Isle [Maine] granite. See the feldspar?" We crouched to get a better view and he pointed out the pale nuggets of feldspar scattered like loose change through what had once been magma. People sidestepped us, yakking into their cell phones and racing to lunch appointments. Some of the feldspar chunks are surrounded with a rim, Fr. Skehan said, tracing the pattern with a fingertip. "It's caused by changing conditions in the magma, and maybe other materials have come into the magma." He paused and stood up. "Lovely stuff," he said. "Just lovely."

Charlotte Bruce Harvey

Charlotte Bruce Harvey is a writer in Westwood, Massachusetts. Her article on the Arctic expedition of Daniel Linehan, SJ, appeared in the Fall 2000 issue of BCM.

Top of page