Jantjakt 6, 1911] 



SCIENCE 



37 



( SPECIAL ARTICLED 



AN INTERMITTENT SPOUTING WELL 



In parts of central Florida bored wells are 

 somewhat extensively used for drainage pur- 

 poses. The wells are drilled through the 

 superficial material and as a rule enter the 

 Vicksburg Limestone of Oligocene age, al- 

 though other porous limestones may serve the 

 same purpose. Many of the wells terminate 

 in cavities in the limestone, while others reach 

 layers of shell or other porous material. Sur- 

 face water entering the wells is carried into 

 the limestone formation. In some localities 

 in the central part of the state these wells 

 have been found very efficient in carrying off 

 surface water and in draining small marsh 

 areas for agricultural purposes. 



One of these drainage wells near Orlando, 

 in Orange County, recently developed the 

 unusual phenomenon of spouting. The well 

 was drilled in 190Y and is located near the 

 edge of a small lake. It is twelve inches in 

 diameter and has a total depth of 260 feet, 

 and is cased 60 feet. The level of permanent 

 underground water at this locality is 33 feet 

 from the surface. Trucking is carried on 

 around the edge of the lake and the well is 

 intended, by carrying off the surplus water, to 

 prevent the lake from rising above a given 

 level, since to do so would flood the farming 

 land. The well is similar in character to the 

 other drainage wells of this locality and, as 

 in the case of most of the other wells, termi- 

 nates in a cavity in the limestone. 



The well was first seen by the writer Oc- 

 tober 4, 1910. At this time the water of the 

 lake stood a few inches above the level of the 

 top of the pipe, and the well was receiving 

 water at much less than its full capacity. At 

 intervals of a few minutes the well would re- 

 verse itself and spout, throwing a column of 

 water into the air. The spouting comes on 

 gradually. First the well ceases to receive 

 water and begins bubbling; the column of 

 water follows, rising with considerable force 

 to a height of twenty feet or more above the 

 surface, the spout occurring with tolerable 

 regularity at intervals of four minutes. The 

 manager of the farm states, however, that the 

 interval between spouts varies from two to 



fifteen minutes, being probably influenced by 

 varying conditions under which the water 

 enters the well.' 



Although drilled three years ago and re- 

 receiving water more or less continuously 

 during that time the phenomenon of spouting 

 developed for the first time on September 26, 

 1910, the first spouting having occurred about 

 eight o'clock in the morning of that day. The 

 well continued spouting without interruption 

 for a little more than a week and until shut 

 off by the owner. 



Various fanciful theories have been ad- 

 vanced to account for the spouting, including 

 supposed occurrence of gas and oil, and the 

 supposed influence of recently formed sinks in 

 the interior of the state. The true explana- 

 tion is evidently much more simple. At this 

 stage of the lake the well is receiving water 

 at less than its full carrying capacity and as 

 the water enters the vertical pipe it forms a 

 suction, carrying a large amount of air into 

 the well, which doubtless collects in a chamber 

 or cavity along the side or at the bottom of 

 the well. As the well continues receiving 

 water the air accumulates under pressure in 

 this chamber until ultimately the pressure 

 under which the air is confined is sufficient to 

 overcome the weight of the overlying water 

 plus the inertia of movement, and hence 

 rushes out with considerable force, carrying 

 the column of water with it. The fact that 

 the well when first drilled did not spout and 

 afterwards began spouting doubtless indicates 

 that the essential conditions were subsequently 

 developed either by caving or by other changes 

 in the underground conditions. 



When partly shut off so that only a limited 

 amount of water enters the well the air taken 

 into the well is able to return to the surface 

 freely and under these conditions spouting 

 ceases. It is probable that if an elbow is 

 placed on the well, allowing the water to enter 

 laterally instead of vertically, the amount of 

 air taken into the well will be so far reduced 

 that the spouting will cease. Likewise when 

 the lake rises so that the water stands several 



^ A photographic illustration of the spouting 

 well will be found in the Third Annual Report of 

 the Florida Geological Survey, pi. 9, 1910. 



