Confronted with a mountain sawed in half, a traveller would naturally speculate about how that might have happened-as had the Indians before, when they supposedly concluded that the Minisink had once been “a deep sea of water.” Samuel Preston agreed with the Indians. In i828, in a letter to Hazard’s Register of Pennsylvania, Preston referred to the Water Gap as “the greatest natural curiosity in any part of the State.” He went on to hypothesize that “from the appearance of so much alluvial or made land above the mountain, there must, in some former period of the world, have been a great dam against the mountain that formed all the settlements called Minisink into a lake, which extended and backed the water at least fifty miles.” And therefore, he worked out, “from the water-made land, and distance that it appears to have backed over the falls in the river, the height must, on a moderate calculation, have been between one hundred and fifty and two co-working space groningen hundred feet, which would have formed a cataract, in proportion to the quantity of water, similar to Niagara.” Preston was a tourist, not a geologist. The first volume of Charles Lyell’s Principles of Geology, the textbook that most adroitly explained the new science to people of the nineteenth century, would not be published for another two years, let alone cross the sea from London. All the more remarkable was Preston’s Hypothesis. Like many an accomplished geologist who would follow, Preston made excellent sense even if he was wrong. Withal, he had the courage of his geology. “If any persons think my hypothesis erroneous,” he concluded, “they may go and examine for themselves ….T he Water Gap will not run away.” While sediments accumulated slowly in the easygoing lowlands of the late Silurian world, iron in the rock was oxidized, and therefore the rock turned red. Alternatively, it could have been co-working space amsterdam red in the first place, if it weathered from a red rock source. There were dark-hued muds and light silts in the outcrop, settled from Silurian floods. There were balls and pillows, climbing ripples, flow rolls, and mini-dunes-multihued structures in the river sands. Maroon. Damask. Carmine. Rouge.