Like a magician I exhibited the artificial geysers before New York and Boston science academies, and gave the summaries of the results of our geyser experiments, as follows: (1) Boiling springs are like other springs, controlled by the head or pressure of underground water in the hills. (2) Upstreaming of heated water and building up of silica (convection is the scientific jargon) may push the vent of a boiling spring even higher than its source (reversed head). (3) In this delicate condition, even rainfall or sinter building up or outburst at a lower level or clogging of a pipe may change spring to geyser or geyser to spring. There are many more boiling springs than there are geysers, and many more hot springs than there are boiling springs, and the word cold means nothing at all. There may be boiling springs under New York City if you go deep enough. That is why the riot of geyser apparatus is worth thinking about. (4) Irregular geysers overflow continually, regular geysers discharge their waters only during eruptions. Both are methods of feeding rivers, just like any other springs. But there is a lot of volcanic heat underground. This brings up the question of how much a volcanic eruption is like a geyser. Geologists apply a glib word, phreatic, to Japan’s Bandai Volcano, which blew steam and rocks out of the side of a mountain and dammed a river. Hawaiian volcanoes squirt liquid basalt up a crack with flames and red fume and sulfur gas, and almost no steam at all. The answer seems to be that the Palisades of the Hudson may once have been Hawaiian lava eruptions and, further, that lava is still erupting there if you go down deep enough. New York doesn’t know about it, but it sensed it in 1886, when it felt the Charleston earthquake. All that Catskill water supply of the great city is in cracks above the level of the deep lava, and extends out under Long Island Sound. If the Hudson fault fissure wiggled a little more than usual, and if the deep lava lowered and pulled down some of the Atlantic water, an eruption like Bandai is not impossible in the Watchung Ridge of New Jersey. This is not likely; but the globe has been through revolutions and cataclysms, and the Watchung explosions might start a new geyser basin. Something like that happened in northwest Wyoming in the Pliocene age, during 11 million years, next preceding the ice ages that began 2 million years ago. And the Yellowstone was the result. We shall see more volcano geysers. Next, the making of deltas became a hobby in our laboratory, in connection with the old leaf deltas scattered on the New England landscape, partly covered with trees within the grounds of the country villas about Boston.