Wells that predict weather changes are local curiosities in many parts of the world. Such wells are not uncommon in the United States. If the well is open at the top, its manifestations consist of occasional disturbance of the water and the discharge of numerous bubbles. If it is covered, a strong current of air is, at times, emitted from any small orifice in the cover. This may be strong enough to lift and blow away light objects placed over the aperture. Its emission is frequently accompanied by a loud whistling or roaring sound. Such occurrences are supposed to betoken an approaching storm. These wells are called “blowing wells”; sometimes “weather wells” or “barometer wells.” In certain cases an indraft of air is sometimes observed; i. e., the well alternately “sucks” and “blows.” As a rule these phenomena correspond to fluctuations in barometric pressure, and therefore are, in a rough way, indicative of changes in weather. It is obvious that a body of air inclosed in the earth and communicating by one or a few small openings with the air above will set up outdrafts and indrafts in adjusting its tension to that of the latter. The amount of air contained in the well itself would not suffice to produce the violent effects observed and it is therefore assumed that the typical blowing well taps a subterranean reservoir of air, probably filling the interstices of sand and gravel beds. When the pressure of the external air is diminished, some of the imprisoned air escapes. For a given body of inclosed air, the smaller the channel or channels by which it emerges, the stronger the outdraft. When the barometric pressure outside increases, the current of air flows in the reverse direction. In winter the indraft of cold air in such a well sometimes causes the water to freeze, even at a depth of 100 feet or more below the surface of the ground, and is therefore a source of inconvenience to the owner. Various other circumstances may give rise to the bubbling and blowing of wells. Carbon dioxide and other gases dissolved in the well water account for the bubbling of many wells, and this process is more active at times of low barometric pressure, because at a given temperature, the amount of gas that the water can hold in solution varies with the pressure. Another cause of the blowing of a well is, in some cases, a sudden rise in the water level (“water table”) in the surrounding ground, as after a heavy rainstorm. If the ground is overlain by an impervious stratum, the air imprisoned between this stratum and the surface of the ground water over an extensive area will escape with violence through any available channel, such as that supplied by the well. Lastly, cases have been described in which subterranean air currents arise from the friction of rapidly flowing underground streams, setting up permanent indrafts or outdrafts through wells communicating with such streams. 5. CURIOUS SHOWERS.