ARTESIAN WELLS.
(Vol. ix., p. 222.)
Your correspondent Stylites is strongly advised not to set about making, or rather endeavouring to make, a well of this description till he has been well advised of the feasibility of the scheme in his particular locality. The old adage will apply in this case, "Ex quovis ligno," &c. It is not everywhere that an artesian well can be obtained with any depth of bore; that is, a well which shall bring its water to or above the surface of the ground. But if, on sufficient knowledge of the mineralogical structure of the country, it be declared that a well of the true artesian sort cannot be obtained, Stylites should dig his well, say fifteen or twenty feet deep, and "stein" it, and then bore in search of a spring, unless a sufficient supply is already obtained from the surface drainage. A moderate outlay in this way, unless the impervious stratum be of very great thickness indeed, will generally bring up water, with a natural tendency to rise within reach of a common pump, or of a well-bucket at the least.
But it may still happen that the water of the bore has not this natural tendency. In that case the sinking of the well may be continued till the water is reached, and a sufficient depth of reservoir obtained at the bottom.
M. (2)
As practical answers to the inquiries of Stylites on this subject, I have to say, that common wells are preferable to artesian in all cases where abundance of water is obtained at a depth not exceeding thirty feet. I need not tell Stylites that the common sucking-pump will not draw up water from a depth exceeding thirty feet. The convenience of common wells is one reason why artesian ones are not universally adopted; and a greater reason is that artesian wells are very much more expensive to make than common ones. When artesian wells are preferable to common ones is, when water cannot be obtained at a depth beyond the reach of the force-pump. Two of my friends have made artesian wells; one a mill-spinner at Dundee, at a time when that town was very ill supplied with water. He sunk a well 150 feet in depth and found no water. A bore was then made through trap rock for upwards of 150 feet, and water was found in abundance on reaching the underlying sandstone. The water ultimately reached near to the top of the well. The other well was made by a bleacher in the neighbourhood of Lisburn in Ireland. All the surface springs in his bleaching-grounds, which are extensive, did not supply a sufficient quantity for his purposes. The subsoil being boulder clay, he had to bore through it to about 300 feet before the water was met with; when it rose as near the top of the bore as to permit the use of a common pump being worked by power. The theory of the action of artesian wells has been explained by Mr. Buckton (Vol. ix., p. 283.), but I have no hesitation in telling Stylites that he will find water almost anywhere in this country by means of an artesian bore.
Henry Stephens.