The Earthquake of 1755: Science v. Religion

Source

“A Great Shaking.” It was still dark on the morning of 18 November 1755, when Harvard professor John Winthrop was jolted awake by the shaking motion of his house. He knew it was an earthquake: he had felt similar tremors in 1727, when he was thirteen, but these were more violent and longer-lasting. He kept to his bed while the house continued to shake around him, and objects fell from their places. When the shocks eventually sub-sided, Winthrop leapt from his bed and struck a light. His pendulum clock said the time was 4:11, but it had stopped, thrown off balance by the first shock. He then looked at his pocket watch, and it was nearly four minutes farther along. The earthquake had lasted about three and a half minutes, but it had been long enough and strong enough to do considerable damage: some fifteen hundred chimneys had been toppled or damaged, and the gable ends of some of the brick houses had collapsed. The quake was felt up and down the east coast. In the days immediately following the earthquake Winthrop learned of a two-foot-wide, thousand-foot-long fissure that had opened in New Hampshire and of ash cushing from cracks in the earth that had opened in a nearby coastal town. At his home Winthrop set to work recording all he could observe of the quake’s effects: he calculated the vertical and lateral velocity of objects that had been pitched from his mantle and from the top of his chimney; from the direction they had fallen he ascertained the direction from which the earthquake had come. Most importantly, when he experienced an after-shock several days later (this time in daylight), he noticed the bricks in his fireplace moving upward, one after another, and immediately dropping back into place. As he described it, the motion was not “of the whole hearth together,” whether from side to side or up and down, “but of each brick moving separately by itself”: it was as if there were a “wave of earth rolling along.” Neither Winthrop nor anyone else fully comprehended the implication of this observation; today the wavelike quality of seismic motion is basic to the understanding of earth-quakes.

An Unscientific Response. Soon Bostonians learned of the devastating earthquake felt in Europe and North Africa only seventeen days before, which had killed more than sixty thousand people in Lisbon, Portugal, and virtually destroyed the city. In an age when earthquakes were little understood (Winthrop’s systematic analysis was exceptional) and in which people accepted that nothing happened without God’s knowledge and approval, it was natural to look for meaning in what modern people consider natural occurrences. Soon Boston’s pulpits rang with sermons warning that these earthquakes were indications of God’s anger. One minister, the Reverend Thomas Prince, republished “Earthquakes, the Works of God and Tokens of his Just Displeasure,” a sermon he had written on the occasion of the 1727 quake. The title suggests its content, but added to the recycled sermon was new information that made Winthrop bristle. Ever since Benjamin Franklin’s famous experiments in electricity, men of science sought electrical influence in almost every field of inquiry. Franklin had even postulated that electricity had a hand in causing earthquakes, a belief enthusiastically seconded by the Reverend Prince, who suggested that the earthquake may actually have been induced by electricity attracted by Boston’s many lightning rods. (Ironically the lightning rod had been invented by Franklin).

Winthrop Attacks. This was too much for Winthrop, who felt that Prince was mixing theology with “junk science.” In response Winthop published “Two Lectures on Earthquakes,” amounting to a direct attack on the orthodox relationship of God and the universe. Winthrop did not accept the widely held belief that God frequently intervened directly in the physical world by manifesting His anger through natural disasters. Winthrop believed instead that God had built an amazingly complex universe that then ran by itself, like a perpetual clock. This universe was absolutely governed by immutable physical laws, laws which could be learned and understood by humans. Thus earthquakes were forces of nature, not “scourges in the hand of the Almighty.”

Appealing to the Public. The public interest in this thorny issue was so great that the Reverend Prince was able to publish his reply on the front page of the Boston Gazette, opening a month-long public debate in that newspaper. Prince responded gently enough, but too condescendingly for the prickly Winthrop’s liking, who came back with a caustic, no-holds-barred reply, ruthlessly taking Prince’s faulty theories to pieces. “Since the earthquake,” claimed Winthrop, “our pulpits have generally rung with terror.” He accused the clergy of exploiting earthquakes, comets, and “other terrifying phenomena... to keep up in mankind a reverent sense of the deity.” Winthrop let his passion for rational science get the better of him, but there was no denying his data, and Prince publicly conceded Winthrop’s points, with somewhat more grace than the younger man had shown in his attacks. Winthrop’s challenge to a centuries-old interpretation of the natural world showcased the scientific method to which he had devoted his life and brought the science-versus-religion debate out of the academy and before an attentive public.

FRANKLINS’S LIGHTNING ROD

The success of Benjamin Franklin’s “Philadelphia Experiment” had a practical application that found instant popularity. Lightning was a serious hazard that frequently shattered chimneys and church steeples, set houses and bams ablaze, and killed people even inside their homes. Franklin first recommended the widespread use of lightning rods in his Poor Richard’s Almanack for 1753. Curiously, Europeans were slow to adopt their use, but Americans embraced the novelty wholeheartedly. In only two years there were so many lightning rods on the houses and public buildings of Boston that one man blamed them for provoking the 1755 earthquake, in the belief that they directed too many lightning bolts into the ground. Fortunately few agreed with this position; in 1772 Franklin could report that “pointed conductors to secure buildings from Lightning have now been in use near 20 Years in America, and are there become so common, that Numbers of them appear on private Houses in every Street of the principal Towns, besides those on Churches, public Buildings, Magazines of Powder, and Gentlemen’s Seats in the Country”

Source: Carl Van Doren, Benjamin Franklin (New York: Viking, 1938).

Source

Bryce Walker, Earthquake (Alexandria, Va.: Time-Life Books, 1982).