The force of the tremor knocked Darwin to his knees. He’d felt the earth move beneath his feet on the slopes of volcanoes, but never such a jolt as this. It felt like the ground had fallen out from under him. The staff in his hand slipped through his fingers and dust began billowing up around his feet. Darwin didn’t feel like he was in danger; in fact, he felt more afraid when climbing tall trees in search of reptiles and insects for his shipboard collections.
Darwin stood and immediately staggered again under the force of another jolt, this time a weaker aftershock. Birds that had settled to the ground in search of security rose up in flocks around him and flew out to sea. Is this how Lyell’s uniformitarian geology works, thought Darwin? Does the earthquake somehow determine the rise and fall of continents? If so, it wasn’t so slow and gradual a process as Lyell thought, occurring over long eons as natural forces worked away at the land. Sometimes of those forces felt downright catastrophic. Perhaps the biblical account had something to recommend it. A smaller shock, building up slowly in intensity shook Darwin from side to side, and his feet struggled to find purchase in the deep gravel beneath his feet.
For some reason, he began thinking about the coral reefs he’d seen from the deck of the Beagle earlier in the voyage. They seemed to rise and then sink beneath the waves because of similar forces — volcanic stresses rather than quakes, but natural nonetheless. Perhaps when the land collapses in an earthquake, somewhere else — simultaneously — another strip of land is being pushed up? Atolls worked this way, he reasoned. As the islands slowly slipped beneath the waves, elaborate coral catacombs built up on their surface, struggling for just enough filtered sunlight to keep themselves alive in the shallow pools. Most of the coral eventually died as fresh new coral heaped up on top of the old. Mountains of coral could build up in this way, even as the original volcanic mount underneath the pile subsided away into the deep.
Maybe earthquakes knocked together new mountains as the sea floor slipped away. Or, earthquakes knocked down the mountains as volcanic action pushed them back up again somewhere else. Sort of a cyclic system might develop that similarly caused the rise and fall of whole continents. Darwin trembled at the thought. His hands began to shake and he felt bile rise in his throat. He’d need to talk to the ship’s doctor about that. He’d been violently ill several times in recent days. But then his mind provided distraction once again. He muttered out loud to no one, “But how to test such a theory?”
Fitzroy’s cabin boy, clinging for dear life to a trunk on the other side of the clearing, interrupted Darwin’s reverie with a shout. “Look out sir, your gear is about to fall in the water. Your clinometer will be lost –“