Longton, Staffordshire.—The Potteries obtain a portion of their supply from a series of wells at Longton, which are shown in the diagrammatic sectional plan, Fig. 234. The well marked No. 1 is 12 feet in diameter, and 135 feet deep in the new red sandstone. When finished the water rose to within 35 feet from the surface. The cost of the first 45 feet was 3l. 10s. a yard; of the second 45 feet, 6l. 10s. a yard; and the third 45 feet, 9l. a yard. When this well was 36 feet down, a large quantity of water was met with, so a heading was driven at that depth in the direction of No. 2 well; this, after 30 feet, passed through a fault which drained off the water, and the sinking of No. 1 was proceeded with. After the engine had been erected and pumping some short time, it was proposed to drive headings from the bottom; but owing to the pumps taking up so much room in the shaft, there was not space enough for sinking operations to be carried on, and No. 2 well was therefore sunk for convenience sake, at the cost of about 30s. a yard. When No. 2 was down 54 feet, a trial bore-hole 3 inches diameter was put down, and water rose in a jet about 3 feet high. The well was then continued to the level of No. 1, and a heading, 39 feet long, driven between the two shafts. No. 2 has now a 12-inch bore-hole at bottom, down 54 feet.

Headings have also been driven W. and N. of No. 2 well, at a cost of 30s. a yard. The western heading is 213 feet long, driven with a slight rise, and gave much water. There are two headings N., running in the direction of the railway, one over the other. The lower was driven level with the bottom of the shaft, but no water met with; the upper is 36 feet from the surface, and is intended to carry away surplus water down to a line of earthenware pipes which are led along the railway to a low-level reservoir.

In the eastern heading there is a rise of 4 feet, owing to the nature of the strata; and after it had been driven 510 feet, well No. 3 was sunk for ventilation and for drawing out material. A bed of very hard sandstone, 63 feet long, was passed, cost 4l. 10s. a yard, and beyond came marl, in which driving cost 45s. a yard. This heading was continued 330 feet beyond No. 3, and an air-hole 3 inches diameter put down 126 yards deep, but no water was met with. The bed of hard sandstone was also found in driving the lower N. heading, which was discontinued after going into it some 5 or 6 feet. The yield from these wells is about 600,000 gallons a day, and recently a new bore-hole at No. 3 well, when down 350 feet, gave some 380,000 gallons a day additional.

Leek.—The Potteries waterworks have also wells at the Wallgrange Springs, near Leek; these rise from the conglomerate beds, and are stated to yield 3,000,000 gallons daily. The water from these springs is pumped into Ladderidge reservoir, and is distributed from thence into the town of Newcastle-under-Lyme and the Potteries.

Middlesborough.—The Figs. 235 to 238 are sections and plans of a well at the works of Messrs. Bolckow and Vaughan, Middlesborough, made under the direction of S. C. Homersham, C.E. A trial hole was first put down to a depth of 398 feet 6 inches, and a shaft afterwards sunk by Messrs. Docwra and Son to that depth, through alternating beds of clay, sand, gypsum, and sandstone. At the bottom of the shaft a bore-hole of 18 inches diameter throughout was made with Mather and Platt’s apparatus to a depth of 1312 feet; the first 1160 feet of which were through new red sandstone interspersed with beds of clay, white sandstone, red marl, and gypsum. Next came 40 feet of gypsum, hard white sandstone, and limestone; and the remaining 100 feet were through red sandstone, pure salt rock, occasional layers of limestone, and then salt rock to the bottom. The gross time spent in sinking this bore-hole was 510 days, or an average of 2 feet 5 inches a day.

Ross, Herefordshire.—The well at the Alton Court Brewery is shown in Figs. 239, 240. The shaft, 5 feet in diameter and 27 feet deep, is steined with 9-inch brickwork for a distance of 17 feet. At the bottom is a 12-inch bore-hole 100 feet 9 inches deep, unlined. The water is abundant. At level of the bore a heading, 6 feet high, 5 feet wide, and 27 long, has been driven, to afford storage room.

Wolverhampton.—This town is partially supplied from wells sunk in the new red sandstone. There are two shafts, 7 feet in diameter and 300 feet deep, a heading 459 feet long, and in this a boring of 390 feet. The yield when first completed was 211,000 gallons a day.

St. Helens, Lancashire.—Supplied with about 570,000 gallons daily from two wells, each 210 feet deep, in the new red sandstone. Each well has a bore-hole at the bottom.

Oolitic Strata.

Northampton.—The well at the waterworks is sunk and bored 253 feet 3 inches in the lias. The shaft is steined with brickwork and iron cylinders in the following order: for 16 feet 9 inches in depth the well is 7 feet 6 inches in diameter, lined with brickwork; at this depth two cast-iron cylinders 5 feet 6 inches diameter are introduced, which are again succeeded by 9-inch brickwork, commencing at 5 feet 6 inches internal diameter and widening out to 7 feet 6 inches in diameter. The bottom of the shaft is floored with bricks at a distance of 120 feet from surface. At this point the bore-hole commences, and for the first 31 feet it is lined with 14-inch pipes, which rise into the shaft 5 feet above the floor. The remaining portion of the bore-hole, 102 feet, is 9 inches diameter.

Swanage, Dorset.—The section and plan, Figs. 241, 242, are of a well at Swanage, sunk 60 feet and bored 53 feet, the lining tube rising 8 feet into the shaft, which is 5 feet 6 inches in diameter, and lined with 9-inch steining. The strata passed through are clays and limestones, and may perhaps be referred to the Purbeck beds. At first this well yielded little or no water, but it now gives a sufficient supply.

Cretaceous Strata.

Bishop Stortford.—The waterworks and well are situate west of the town, near the farm buildings known as Marsh Barns. The shaft is 160 feet deep, the bore-hole 140 feet. The following is a section of the strata;—

The water rises to within 140 feet of the surface of the ground. The yield is 10,000 gallons a minute; only 25 gallons a minute from the bore; the rest from the headings driven north and south respectively at a depth of 154 feet.

Braintree.—The well sunk for the Local Board is in a field near Pod’s Brook. The shaft is 8 feet in diameter, steined with 9-inch steining, and carried down 55 feet, the remainder of the well being bored. Strata;—

The level of the ground is 140 feet above the sea-level; water stands 29 feet deep; yield about 11,500 gallons an hour.

Brighton.—This town has always been supplied from wells sunk in the chalk. One well is sunk near the Lewes Road, and has a total length of 2400 feet of headings driven in a direction parallel with the sea, and at about the coast-level of low water. These headings intercept many fissures and materially add to the yield.

A second well was sunk in 1865, at Goldstone Bottom, and headings driven to the extent of about a quarter of a mile across the valley parallel to the sea.

Goldstone Bottom is a naturally formed basin in the chalk, the lowest side of which, nearest the sea, is more than 60 feet higher than the middle or bottom of the basin. The water is obtained as at Lewes Road, from fissures running generally at right-angles to the coast-line, but they are of much larger size and at far greater distances from each other; whereas at the Lewes Road well it is rare that 30 feet of headings were driven without finding a fissure, and the yield of the largest was not more than 100 to 150 gallons a minute. At Goldstone nearly 160 feet were traversed without any result, and then an enormous fissure was pierced which yielded at once nearly 1000 gallons a minute; and the same interval was found between this and the next fissure, which was of a capacity nearly as large. The total length of the headings at Goldstone Bottom is 13,000 feet. The yield from each well is about 3,000,000 gallons daily.

Chelmsford.—The well belonging to the Local Board of Health, situated at Moulsham, yields about 95,000 gallons of water a day. It is sunk for 200 feet; the rest bored. Water overflowed at first, but now that the well is in use and pumped from, the water only rises to 76 feet from the surface. The following strata were pierced;—

Cheshunt, New River Company.—Situate at the engine-house between the two reservoirs. The well is 171 feet deep, and is steined partly with brickwork and partly with iron cylinders. For 12 feet in depth the well is 11 feet 6 inches in diameter, and steined with 14-inch brickwork; for a farther depth of 44 feet it is 9 feet diameter, and steined with 9-inch brickwork; of the 44 feet, 41 feet are lined with cast-iron cylinders, 8 feet diameter, which are also carried to a depth of 105 feet from the surface. There are fifteen cylinders of this size in use, and they are succeeded by others 6 feet 10 inches diameter, of which there are six in use; these are again succeeded by two cylinders 6 feet diameter. The whole of the cylinders are 6 feet in depth. The bottom of the last cylinder is 118 feet from the surface, at which point they rest upon a foundation of 9-inch brick steining 7 feet in depth. At the bottom of the 6-feet cylinders the well widens out in the form of a cone 12 feet 6 inches diameter at the floor, which is 26 feet below the bottom of the 6-feet cylinder. In the centre of the well a bore-hole, 3 inches diameter and 27 feet deep, was made, and the well is provided on the floor-level with headings.

Dorking, Surrey, obtains its water supply from a well sunk into the outcrop of the lower greensand, at the south side of the town. The shaft is 11 feet in diameter and 160 feet deep, steined with 9-inch work laid dry. The yield is not more than 30 gallons a minute, owing to the unfortunate position of the well, but might be considerably increased if suitable means were adopted.

Harrow Waterworks.—The well is situate 430 yards to the west of the church. The surface of the ground is 226 feet above the Ordnance datum. There is a shaft for 193¹⁄₂ feet; the rest is a bore. In a bed of dark red sand 144 feet down, the water was very foul. Strata;—

Water rises to a height of 125 feet below the surface. The yield is about 190 gallons a minute.

Highbury, Middlesex.—Well at the residence of H. Rydon, Esq., New Park. Figs. 243 to 245. The shaft is 4 feet 6 inches diameter, and 136 feet deep, steined with 9-inch work set in cement. The bore was commenced with a 12-inch hole, but the character of the ground was such that the successive reductions in size, shown in the enlarged section of the lining tubes, Fig. 245, had to be made. When in the chalk the bore was continued some 48 feet unlined. The strata passed were;—

Kentish Town.—This well was sunk under the supposition that as the outcrop of the subcretaceous formations was continuous around the margin of the cretaceous basin surrounding and underlying the London tertiaries, except at the eastern border, those subcretaceous formations would be found under London, just as they actually were at Paris. This proved to be the case until the gault was passed, when a series of sandstones and clays was encountered, occupying the place of the lower greensand, but evidently of older geological character, and having many of the features of the new red sandstone.

The surface of the ground, Fig. 246, is 174 feet above Thames high-water mark. There is a shaft for 539 feet; the remainder being bored. The following detailed account of the strata is due to Prestwich.

The engravings, Figs. 246 to 249, which are on the authority of G. R. Burnell, do not exactly agree with Prestwich’s section, but in the main they are both alike. The following summary may be found of service;—

Michelmersh, Hants.—Fig. 250 shows a section of a well in this village, comprised within the writer’s practice. The shaft is 4 ft. 6 in. in diameter and 400 feet deep, steined both above and below the chalk with 9-inch work, the upper course having rings of cement at every 12 inches.

The strata pierced were;—

The water rises some 19 feet in the shaft, and is abundant, although up to the present its quantity has not been tested.

Mile End, Middlesex.—Well at Charrington, Head, and Co.’s brewery. Figs. 251 to 253. The surface is 33¹⁄₂ feet above Trinity high-water mark.

In the upper part there are three iron cylinders built upon 9-inch brickwork, which is carried down into the mottled clay. A 9-inch iron cylinder, partially supported by rods from the surface, rises some 28 feet into the brick shaft into which it is built by means of rings. Another iron cylinder is carried down into the chalk, the space between the cylinders being filled in with concrete.

The strata passed were;—

The water-level is some 103 feet from surface, and the yield 60,000 to 70,000 gallons a day.

Norwich.—Well at Coleman’s works. After a few feet of alluvium the borer passed through hard chalk with flints at distances of about 6 or 7 feet apart, for 700 feet, with the exception of 10 feet at the depth of 500 feet where the rock was soft and of a rusty colour, thence the flints were thicker, namely, about 4 feet apart to the depth of 1050 feet. After this 102 feet were pierced of chalk, free from flints, to the upper greensand, a stratum of about 6 feet, and then gault for 36 feet. The whole boring being full of water to within 16 feet of the surface.

Section of strata;—

Paris.—The wells sunk in the Paris basin, of which Fig. 254 is a section, are very numerous, and many of them of great depth. Fig. 255 is a plan indicating the position of the principal wells, and Figs. 256 to 258 sections giving each a summary of the nature and thickness of the formations passed through.

For boring these wells special tools had to be used, which have already been described at length in Chap. VI.

A large Artesian well was, in 1867, being constructed by Dru at Butte-aux-Cailles, Fig. 255, for the supply of the city of Paris, which is intended to be carried down through the greensand to a depth of 2600 or 2900 feet to reach the Portland limestone. The boring in 1867 was 490 feet deep, and its diameter 47 inches.

During the previous 2¹⁄₂ years, M. Dru was engaged in sinking a similar well of 19 inches diameter for supplying the Sugar Refinery of M. Say, in Paris, Fig. 255; 1570 feet deep of this well had been bored in 1867, see Fig. 258.

The well at Grenelle was sunk by Mulot in 1832, and after more than eight years’ incessant labour, water rose on the 26th of February, 1842, from the total depth of 1806 feet 9 inches. The diameter of the bore-hole is 8 inches, ending, as is seen in the detail sections, Figs. 259 to 262, in the lower greensand.

The well of Passy was intended to be executed in the Paris basin which it was to traverse with a diameter, hitherto unattempted, of 1 mètre (3·2809 feet); that of the Grenelle well being only 20 centimètres (8 inches). It was calculated that it would reach the water-bearing stratum at nearly the same depth as the latter, and would yield 8000 mètres or 10,000 cubic mètres in twenty-four hours, or about 1,786,240 gallons to 2,232,800 gallons a day.

Figs. 263 to 266 show a detail section of the strata passed.