To present the geologist's side of the question is to sound a some-What pessimistic outlook regarding Shanghai's artesian wells, but as. the geologist Is always taken into consideration when the engineer is making his computations, it is well to give his views first.
The opinion of Dr. George B. Cressey, whose research work Chinese" geography and geology is Widely recognized as making him a authority, points out that an art sian well' is one in which water is Furthermore, Dr. Cressy holds that these Tenses seem to be more continuous north and south than in an east and west direction, that they are in fact the ancient beaches of the old shore line, Shanghai itself having been in the oologist's stupendous computations, at one time directly on the sea. "Exam tion of sand taken from diggings in this north to south direction shows that it is fossil beach deposits, and under a microscope it can be seen clearly by the geologist that it has been rounded by waves, that it in every respect, sea-sard, and a3 such, points to the old Shore line at some distant age in the world's history, sweeping gracefully round what is now Shanghai.
Dr. Cressey maintains, therefore, that a certain similarity in depth of sand and character of the water would be found in wells dug along this So far, Rowever, unfortunately for the purposes of this prediction, most of Shanghai's artesian wells have been dug in the east. to west direc Int conclusion he declares that the artesian possibilities of Shanchai are decidedly limited, and that the city itself could never depend sold nupes well water for its needs. other words, the supply. which Is of believed' to be constantly replenished, could be exhausted. There are no hidden springs, according to Dr, Gressey, under Shanghai.
The Other Side of the Question Other parts of China, however, have great artesian well possibili ties and this brings one to the other Nide of the question represented by Col. M. Ti. Logan, of. INST. ct, foreed above the surface, certain natural causes combining to do this Strictly speaking, therefore, Shanghai is not an artesian district, Another canential for a real artesian well district is that there should '4 continuous bed underlying the suc-aco, either of sand, or, in the case of that underneath London, of por-cons balk. Shanghai has'no auch underlying continuous bed.
Geology shows that its uppermost strata is mainly mud, and that approximately 1,000 feet below the surface the bed rock can be struck.
Scattered through the mud are numerous layers of sand, clay and the various compositions of interes to the geologist, but not necessary to explain for the purposes of this description, Interspersed in the mud, also, are the "lenses" of and bearing water, so-called eeawse of their oblong shape like a lens. Bach Tens bears water, some good a some bad, and each varies in size and depth, De. Cressey points out that this accounts for the great variety of depths at which good ater may be obtained in the Shanghai district, There ix no con-juans bed, he says, of sand which ours water,
Text read from the printed page and cleaned; old type leaves the occasional error.