The shell-pump, for raising the material broken up by the boring-head, is shown in Figs. 197, 198, and consists of a cylindrical shell or barrel P of cast-iron, about 8 feet long and a little smaller in diameter than the size of the bore-hole. At the bottom is a clack A opening upwards, somewhat similar to that in ordinary pumps; but its seating, instead of being fastened to the cylinder P, is in an annular frame C, which is held up against the bottom of the cylinder by a rod D passing up to a wrought-iron bridge E at the top, where it is secured by a cotter F. Inside the cylinder works a bucket B, similar to that of a common lift-pump, having an indiarubber disc valve on the top side; and the rod D of the bottom clack passes freely through the bucket. The rod G of the bucket itself is formed like a long link in a chain, and by this link the pump is suspended from the shackle O, Fig. 192, at the end of the flat rope, the bridge E, Fig. 197, preventing the bucket from being drawn out of the cylinder. The bottom clack A is made with an indiarubber disc, which opens sufficiently to allow the water and smaller particles of stone to enter the cylinder; and in order to enable the pieces of broken rock to be brought up as large as possible, the entire clack is free to rise bodily about 6 inches from the annular frame C, as shown in Fig. 197, thereby affording ample space for large pieces of rock to enter the cylinder, when drawn in by the up stroke of the bucket.
The general working of the boring machine is as follows. The winding drum C, Fig. 189, is 10 feet diameter in the large machine, and is capable of holding 3000 feet length of rope 41⁄2 inches broad and 1⁄2 inch thick. When the boring-head B is hooked on the shackle at the end of the rope A, its weight pulls round the drum and winding engine, and by means of a break it is lowered steadily to the bottom of the bore-hole; the rope is then secured at that length by screwing up tight the clamp J. The small steam jet N, Figs. 192, 193, is next turned on, for starting the working of the percussion cylinder H; and the boring-head is then kept continuously at work until it has broken up a sufficient quantity of material at the bottom of the bore-hole. The clamp J which grips the rope is made with a slide and screw I, Fig. 192, whereby more rope can be gradually given out as the boring-head penetrates deeper in the hole. In order to increase the lift of the boring-head, or to compensate for the elastic stretching of the rope, which is found to amount to 1 inch in each 100 feet length, it is simply necessary to raise the top pair of tappets on the tappet rods whilst the percussive motion is in operation. When the boring-head has been kept at work long enough, the steam is shut off from the percussion cylinder, the rope unclamped, the winding engine put in motion, and the boring-head wound up to the surface, where it is then slung from an overhead suspension bar Q, Fig. 189, by means of a hook mounted on a roller for running the boring-head away to one side, clear of the bore-hole.
The shell-pump is next lowered down the bore-hole by the rope, and the débris pumped into it by lowering and raising the bucket about three times at the bottom of the hole, which is readily effected by means of the reversing motion of the winding engine. The pump is then brought up to the surface, and emptied by the following very simple arrangement: it is slung by a traversing hook from the overhead suspension bar Q, Fig. 189, and is brought perpendicularly over a small table E in the waste tank T; and the table is raised by the screw S until it receives the weight of the pump. The cotter F, Fig. 197, which holds up the clack seating C at the bottom of the pump, is then knocked out; and the table being lowered by the screw, the whole clack seating C descends with it, as shown in Fig. 198, and the contents of the pump are washed out by the rush of water contained in the pump cylinder. The table is then raised again by the screw, replacing the clack seating in its proper position, in which it is secured by driving the cotter F into the slot at the top; and the pump is again ready to be lowered down the bore-hole as before. It is sometimes necessary for the pump to be emptied and lowered three or four times in order to remove all the material that has been broken up by the boring-head at one operation.
The rapidity with which these operations may be carried on is found in the experience of the working of the machine to be as follows. The boring-head is lowered at the rate of 500 feet a minute. The percussive motion gives twenty-four blows a minute; this rate of working continued for about ten minutes in red sandstone and similar strata is sufficient for enabling the cutters to penetrate about 6 inches depth, when the boring-head is wound up again at the rate of 300 feet a minute. The shell-pump is lowered and raised at the same speeds, but only remains down about two minutes; and the emptying of the pump when drawn up occupies about two or three minutes.
In the construction of this machine it will be seen that the great desideratum of all earth boring has been well kept in view; namely, to bore-holes of large diameter to great depths with rapidity and safety. The object is to keep either the boring-head or the shell-pump constantly at work at the bottom of the bore-hole, where the actual work has to be done; to lose as little time as possible in raising, lowering, and changing the tools; to expedite all the operations at the surface; and to economize manual labour in every particular. With this machine, one man standing on a platform at the side of the percussion cylinder performs all the operations of raising and lowering by the winding engine, changing the boring-head and shell-pump, regulating the percussive action, and clamping or unclamping the rope: all the handles for the various steam valves are close to his hand, and the break for lowering is worked by his foot. Two labourers attend to changing the cutters and clearing the pump. Duplicate boring-heads and pumps are slung to the overhead suspension bar Q, Fig. 189, ready for use, thus avoiding all delay when any change is requisite.
As is well known by those who have charge of such operations, in well boring innumerable accidents and stoppages occur from causes which cannot be prevented, with however much vigilance and skill the operations may be conducted. Hard and soft strata intermingled, highly-inclined rocks, running sands, and fissures and dislocations are fruitful sources of annoyance and delay, and sometimes of complete failure; and it will therefore be interesting to notice a few of the ordinary difficulties arising out of these circumstances. In all the bore-holes yet executed by this system, the various special instruments used under any circumstances of accident or complicated strata are fully shown in Figs. 199 to 207.
The boring-head while at work may suddenly be jammed fast, either by breaking into a fissure, or in consequence of broken rock falling upon it from loose strata above. All the strain possible is then put upon the rope, either by the percussion cylinder or by the winding engine; and if the rope is an old one or rotten it breaks, leaving perhaps a long length in the hole. The claw grapnel, shown in Fig. 199, is then attached to the rope remaining on the winding drum, and is lowered until it rests upon the slack broken rope in the bore-hole. The grapnel is made with three claws A A centred in a cylindrical block B, which slides vertically within the casing C, the tail ends of the claws fitting into inclined slots D in the casing. During the lowering of the grapnel, the claws are kept open, in consequence of the trigger E being held up in the position shown in Fig. 199, by the long link F, which suspends the grapnel from the top rope. But as soon as the grapnel rests upon the broken rope below, the suspending link F continuing to descend allows the trigger E to fall out of it; and then in hauling up again, the grapnel is lifted only by the bow G of the internal block B, and the entire weight of the external casing C bears upon the inclined tail ends of the claws A, causing them to close in tight upon the broken rope and lay hold of it securely. The claws are made either hooked at the extremity or serrated. The grapnel is then hauled up sufficiently to pull the broken rope tight, and wrought-iron rods 1 inch square with hooks attached at the bottom are let down to catch the bow of the boring-head, which is readily accomplished. Two powerful screw-jacks are applied to the rods at the surface, by means of the step-ladder shown in Fig. 201, in which the cross-pin H is inserted at any pair of the holes, so as to suit the height of the screw-jacks.
If the boring-head does not yield quickly to these efforts, the attempt to recover it is abandoned, and it is got out of the way by being broken up into pieces. For this purpose the broken rope in the bore-hole has first to be removed, and it is therefore caught hold of with a sharp hook and pulled tight in the hole, while the cutting grapnel, shown in Fig. 200, is slipped over it and lowered by the rods to the bottom. This tool is made with a pair of sharp cutting jaws or knives I I opening upwards, which in lowering pass down freely over the rope; but when the rods are pulled up with considerable force, the jaws nipping the rope between them cut it through, and it is thus removed altogether from the bore-hole. The solid wrought-iron breaking-up bar, Fig. 203, which weighs about a ton, is then lowered, and by means of the percussion cylinder it is made to pound away at the boring-head, until the latter is either driven out of the way into one side of the bore-hole, or broken up into such fragments as that, partly by the shell-pump and partly by the grapnels, the whole obstacle is removed. The boring is then proceeded with again, the same as before the accident.
The same mishap may occur with the shell-pump getting jammed fast in the bore-hole, as illustrated in Fig. 208; and the same means of removing the obstacle are then adopted. Experience has shown the danger of putting any greater strain upon the rope than the percussion cylinder can exert; and it is therefore usual to lower the grapnel rods at once, if the boring-head or pump gets fast, thus avoiding the risk of breaking the rope.
The breaking of a cutter in the boring-head is not an uncommon occurrence. If, however, the bucket grapnel, or the small screw grapnel, Fig. 202, be employed for its recovery, the hole is readily cleared without any important delay. The screw grapnel, Fig. 202, is applied by means of the iron grappling rods, so that by turning the rods the screw works itself round the cutter or other similar article in the bore-hole, and securely holds it while the rods are drawn up again to the surface. The bucket grapnel, Fig. 206, is also employed for raising clay, as well as for the purpose of bringing up cores out of the bore-hole, where these are not raised by the boring-head itself in the manner already described. The action of this grapnel is nearly similar to that of the claw grapnel, Fig. 199; the three jaws A A, hinged to the bottom of the cylindrical casing C, and attached by connecting rods to the internal block B sliding within the casing C, are kept open during the lowering of the tool, the trigger E being held up in the position shown in Fig. 206, by the long suspending link F. On reaching the bottom, the trigger is liberated by the further descent of the link F, which, in hauling up again, lifts only the bow G of the internal block B; so that the jaws A are made to close inwards upon the core, which is thus grasped firmly between them and brought up within the grapnel. Where there is clay or similar material at the bottom of the bore-hole, the weight of the heavy block B in the grapnel causes the sharp edges of the pointed jaws to penetrate to some depth into the material, a quantity of which is thus enclosed within them and brought up.
Another grapnel that is also used where a bore-hole passes through a bed of very stiff clay is shown in Fig. 207, and consists of a long cast-iron cylinder H fitted with a sheet-iron mouthpiece K at the bottom, in which are hinged three conical steel jaws J J opening upwards. The weight of the tool forces it down into the clay with the jaws open; and then on raising it the jaws, having a tendency to fall, cut into the clay and enclose a quantity of it inside the mouthpiece, which on being brought up to the surface is detached from the cylinder H and cleaned out. A second mouthpiece is put on and sent down for working in the bore-hole while the first is being emptied, the attachment of the mouthpiece to the cylinder being made by a common bayonet-joint L, so as to admit of readily connecting and disconnecting it.
A running sand in soft clay is, however, the most serious difficulty met with in well boring. Under such circumstances the bore-hole has to be tubed from top to bottom, which greatly increases the expense of the undertaking, not only by the cost of the tubes, but also by the time and labour expended in inserting them. When a permanent water supply is the main object of the boring, the additional expense of tubing the bore-hole is not of much consequence, as the tubed hole is more durable, and the surface water is thereby excluded; but in exploring for mineral it is a serious matter, as the final result of the bore-hole is then by no means certain. The mode of inserting tubes has become a question of great importance in connection with this system of boring, and much time and thought having been spent in perfecting the method now adopted, its value has been proved by the repeated success with which it has been carried out.
The tubes used by Mather and Platt are of cast-iron, varying in thickness from 5⁄8 to 1 inch according to their diameter, and are all 9 feet in length. The successive lengths are connected together by means of wrought-iron covering hoops 9 inches long, made of the same outside diameter as the tube, so as to be flush with it. These hoops are from 1⁄4 to 3⁄8 inch thick, and the ends of each tube are reduced in diameter by turning down for 41⁄2 inches from the end, to fit inside the hoops, as shown in Fig. 209. A hoop is shrunk fast on one end of each tube, leaving 41⁄2 inches of socket projecting to receive the end of the next tube to be connected. Four or six rows of screws with countersunk heads, placed at equal distances round the hoop, are screwed through into the tubes to couple the two lengths securely together. Thus a flush joint is obtained both inside and outside the tubes. The lowest tube is provided at the bottom with a steel shoe, having a sharp edge for penetrating the ground more readily.
In small borings, from 6 to 12 inches diameter, the tubes are inserted into the bore-hole by means of screw-jacks, by the simple and inexpensive method shown in Figs. 210, 211. The boring machine foundation A A, which is of timber, is weighted at B B by stones, pig iron, or any available material; and two screw-jacks C C, each of about 10 tons power, are secured with the screws downwards, underneath the beams D D crossing the shallow well E, which is always excavated at the top of the bore-hole. A tube F having been lowered into the mouth of the bore-hole by the winding engine, a pair of deep clamps G are screwed tightly round it, and the screw-jacks acting upon these clamps force the tube down into the ground. The boring is then resumed, and as it proceeds the jacks are occasionally worked, so as to force the tube if possible even ahead of the boring tool. The clamps are then slackened and shifted up the tubes, to suit the length of the screws of the jacks; two men work the jacks, and couple the lengths of tubes as they are successively added. The actual boring is carried on simultaneously within the tubes, and is not in the least impeded by their insertion, which simply involves the labour of an additional man or two.
A more perfect and powerful tube-forcing apparatus is adopted where tubes of from 18 to 24 inches diameter have to be inserted to a great depth, an illustration of which is afforded by an extensive piece of work at the Horse Fort, standing in the channel at Gosport. This fort is a huge round tower, as shown in Fig. 212; and to supply the garrison with fresh water, a bore-hole is sunk into the chalk. A cast-iron well A, consisting of cylinders 6 feet diameter and 5 feet long, has been sunk 90 feet into the bed of the channel in the centre of the fort, and from the bottom of this well an 18-inch bore-hole B is now in progress. The present depth is 400 feet, and the bore-hole is tubed the whole distance with cast-iron tubes 1 inch thick, coupled as before described.
The method of inserting these tubes is shown in Fig. 213. Two wrought-iron columns C C, 6 inches diameter, are firmly secured in the position shown, by castings bolted to the flanges of the cylinders A A forming the well, so that the two columns are perfectly rigid and parallel to each other. A casting D, carrying on its under side two 5-inch hydraulic rams I I of 4 feet length, is formed so as to slide freely between the columns, which act as guides; the hole in the centre of this casting is large enough to pass a bore-tube freely through it, and by means of cotters passed through the slots in the columns the casting is securely fixed at any height. A second casting E, exactly the same shape as the top one, is placed upon the top of the tubes B B to be forced down, a loose wrought-iron hoop being first put upon the shoulder at the top of the tube, large enough to prevent the casting E from sliding down the outside of the tubes; this casting or crosshead rests unsecured on the top of the tube and is free to move with it. The hydraulic cylinders I, with their rams pushed home, are lowered upon the crosshead E, and the top casting D to which they are attached is then secured firmly to the columns C by cottering through the slots. A small pipe F, having a long telescope joint, connects the hydraulic cylinders I with the pumps at the surface which supply the hydraulic pressure. By this arrangement a force of 3 tons on the square inch, or about 120 tons total upon the two rams, has frequently been exerted to force down the tubes at the Horse Fort. After the rams have made their full stroke of about 3 feet 6 inches, the pressure is let off, and the hydraulic cylinders I with the top casting D slide down the rams resting on the crosshead E, until the rams are again pushed home. The top casting D is then fixed in its new position upon the columns C, by cottering fast as before, and the hydraulic pressure is again applied; and this is repeated until the length of two tubes, making 18 feet, has been forced down. The whole hydraulic apparatus is then drawn up again to the top, another 18 feet of tubing added, and the operation of forcing down resumed. The tubes are steadied by guides at G and H, Fig. 213, shown also in the plans.
The boring operations are carried on uninterruptedly during the process of tubing, excepting only for a few minutes when fresh tubes are being added. It will be seen that the cast-iron well is in this case the ultimate abutment against which the pressure is exerted in forcing the tubes down, instead of the weight of the boring machine with stones and pig iron added, as in the case where the screw-jacks are used; the hydraulic method was designed specially for the work at Gosport, and has acted most perfectly. Both the cast-iron well and the bore-hole are entirely shut off from all percolation of sea-water, by first filling up the well 30 feet with clay round the tubes, and making the tubes themselves water-tight at the joints at the time of putting them together.
In the event of any accident occurring to the tubes while they are being forced down the bore-hole, such as requires them to be drawn up again out of the hole, the prong grapnel, Fig. 204, is employed for the purpose, having three expanding hooked prongs, which slide down readily inside the tube, and spring open on reaching the bottom; the hooks then project underneath the edge of the tube, which is thus raised on hauling up the grapnel. In case the tubes get disjointed and become crooked during the process of tubing, the long straightening plug, Fig. 205, consisting of a stout piece of timber faced with wrought-iron strips, is lowered down inside them; above this is a heavy cast-iron block, the weight of which forces the plug past the part where the tubes have got displaced, and thereby straightens them again.
Although there are few localities where the geological formation is not favourable to the yield of pure water if a boring be carried deep enough, yet it rarely happens that free-flowing wells such as those in Paris and Hull are the result. Generally after the water-bearing strata have been pierced, the level to which the water will rise is at some depth below the surface of the ground; and only by the aid of pumps can the desired supply be brought to the surface. Various pumping arrangements have therefore been adopted to suit the different conditions that are met with.
It is not the object of the present work to treat of the forms and fittings of pumps, and the following details are only given as completing Mather and Platt’s system.
It is always desirable to sink a cast-iron well, such as that at the Horse Fort, as nearly as possible down to the level at which the water stands in the bore-hole. The sinking of such a well is rendered an easy and rapid operation, with the aid of the boring machine in winding out the material from the bottom, and keeping the sinkers dry by the use of the dip-bucket, shown in Figs. 214 to 216, which will lift from 50 to 100 gallons of water a minute, for taking off the surface drainage. A well having thus been made down to the level of the water in the bore-hole, the permanent pumps are then applied to the bore-hole as follows, the size of the pumps varying according to the diameter of the bore-hole. Taking the case of a 15-inch bore-hole, a pump barrel consisting of a plain cast-iron cylinder, say 12 inches diameter and 12 feet long, as shown in section in Fig. 219, is attached at the bottom of cast-iron or copper pipes, which are 1⁄4 inch larger in diameter than the pump barrel, and are coupled together in lengths by flanges, Fig. 217. By adding the requisite number of lengths of pipe at the top, the pump barrel is lowered to any desired depth down the bore-hole: the nearer to the depth of the water-bearing strata the better. The topmost length of pipe has a broad flange at its upper end, which rests upon a preparation made to receive it on the cast-iron bottom of the well, as at C in Fig. 219.
A pump bucket D, Fig. 219, with a water passage through it and a clack on the top side, is then lowered into the barrel, being suspended by a solid wrought-iron pump-rod E, which is made up of lengths of 30 feet coupled together by right-and-left-hand screw-couplings, as in Fig. 218. A second bucket F of similar form is also lowered into the pump barrel, above the first bucket, and is suspended by hollow rods G coupled together in the manner just described; the inside diameter of the hollow rods G being such that the couplings of the solid rods E may pass freely through. The pump-rods are carried up the well A to the surface, where the hollow rod of the top bucket is attached to the horizontal arm of a bell-crank lever H, Fig. 219; and the solid rod of the bottom bucket, passing up through the hollow rod of the top bucket, is suspended from the horizontal arm of a second reversed bell-crank lever K, facing the first lever H. As the extremities of the horizontal arms of the levers meet over the centre of the well, one of them is made with a forked end to admit of the other passing it. The vertical arms of the two levers are coupled by a connecting rod L, and a reciprocating motion is given to them by means of an oscillating steam cylinder M, the piston-rod of which is attached direct to the extremity of one of the vertical arms; a crank and flywheel N are also connected to the levers, for controlling the motion at the ends of the stroke. With the proportion shown in the Figure of 3 to 4 between the horizontal and vertical arms of the bell-crank levers, the stroke of 5 feet 4 inches of the steam piston gives 4 feet stroke of the pump. The reciprocating motion of the reversed bell-crank levers causes the two buckets to move always in opposite directions, so that they meet and separate at each stroke of the engine. A continuous flow of water is the result, for when the top bucket is descending, the bottom bucket is rising and delivering its water through the top bucket; and when the top bucket rises, it lifts the water above it while the bottom bucket is descending, and water rises through the descending bottom bucket to fill the space left between the two buckets. In this way the effect of a double-acting pump is produced.
Although a continuous delivery of water is thus obtained of equal amount in each stroke, it is found in practice that a heavy shock is occasioned at each end of the stroke, in consequence of both the buckets starting and stopping simultaneously, causing the whole column of water to be stopped and put into motion again at each stroke. As an air-vessel for keeping up the motion of the water is inapplicable in such a situation, a modified arrangement of the two bell-crank levers has been adopted, which answers the purpose, causing each bucket at the commencement of its up stroke to take the lift off the other, before the up stroke of the latter is completed. By this means all shock is avoided, as the first bucket gently and gradually relieves the second, before the return stroke of the second commences.
In this improved pumping motion, which is shown in Figs. 220, 221, the two bell-crank levers H and K, working the pump buckets, are centred one above the other, the upper one being inverted; the vertical arms are slotted, and are both actuated by the same crank-pin working in the slots, the revolution of the crank thus giving an oscillating movement to the two levers through the extent of the arcs shown by the dotted lines in Fig. 220. The solid pump-rod E suspending the bottom bucket D is attached to the upper bell-crank lever K, and the hollow rod G of the top bucket is suspended from the lower lever H; the crank-shaft J working the levers is made to revolve in the direction shown by the arrow in Fig. 220, by means of gearing driven by the horizontal steam-engine P.
The result of this arrangement is, that in the revolution of the crank the dead point of one of the levers is passed before that of the other is reached; so that the bucket which first comes to rest at the end of its stroke is started into motion again before the second bucket comes to rest. Thus in the lifting stroke of the bottom bucket worked by the upper lever K, the bucket in ascending has only reached the position shown at D in Fig. 220, at the moment when the top bucket worked by the lower lever H arrives at the bottom extremity of its stroke, and the bottom bucket D, which is still rising, continues to lift until it reaches its highest position, by which time the top bucket has got well into motion in its up stroke, and is in its turn lifting the water.
Durham.—Large quantities of water are pumped from the lower Permian sandstone beneath the magnesian limestone of this county, and are used for the supply of the towns of Sunderland, South Shields, Jarrow, and many villages. The quantity, calculated by Daglish and Foster to reach five millions of gallons a day, is obtained from an area of fifty square miles overlying the coal measures. The water-level has not been lowered in the rock by these operations. Along the coast it is that of mean tide, and inland rises to a level of 180 feet. In the coal measures below there is little water, and that little is saline. Sedgwick gives the strata as red gypseous marls, 100 feet; thin bedded grey limestone, 80 feet; red gypseous marls, slightly salt, 200 feet; magnesian limestone, 500 feet; marl slate, 60 feet; lower red sandstone, 200 feet.
Coventry.—Warwickshire. The town is supplied with 750,000 gallons of water a day from two bore-holes made in the bottom of the reservoir. The bore-holes are respectively 6 inches and 8 inches diameter, and 200 feet and 300 feet deep. The town is situated on the Permian formation, but Latham states that the supply is procured from the red sandstone, and, from observations made, it has been found that the two bore-holes yield water at the rate of 700 gallons a minute.
Birkenhead.—There are here several deep wells belonging to the Tranmere Local Board, the Birkenhead Commissioners, and the Wirral Water Company, yielding together about 4,000,000 gallons a day. Figs. 222, 223, show a section and plan of the No. 2 or new engine well at the Birkenhead Waterworks. The shaft is 7 feet diameter for 105 feet, with a bore-hole 26 inches for 35 feet, 18 inches for 16 feet, 12 inches for 99 feet, and 7 inches for 150 feet, or a total depth from surface of 405 feet. The water-level is about 95 feet from surface when the engine is not at work. At the upper water-level, shown in the 26-inch hole, the yield was at the rate of 1,807,400 gallons in twenty-four hours, at the lower level at the rate of 2,000,000 gallons in the same time. At the water-level indicated in the 7-inch bore, water was met with in large quantities. The old engine well is almost identical.
Fig. 222. New Engine Well, Birkenhead Waterworks.
Fig. 223. PLAN
Fig. 224. Well at Aspinall’s Brewery, Birkenhead.
Fig. 225. PLAN
Fig. 226. Enlarged Parts
at A. A
at B. B
at C. C
at D. D
at E. E
Figs. 224, 225, are a section and plan, and Fig. 226 enlarged parts of the well at Aspinall’s brewery, Birkenhead. It consists of a shallow shaft 5 feet in diameter and steined, continued by means of iron cylinders 3 feet 3 inches in diameter and 50 feet in depth. When sand with much water of poor quality was met with, a series of lining tubes was introduced from the point A A, the space between these and the cylinders being filled with concrete. The tubes were discontinued at the sandstone, and the lowest portion of the hole, 3 inches in diameter, is unlined. The water overflows.
Figs. 227, 228, are a section and plan of the well at Cook’s brewery, Birkenhead. The shaft is 6 feet diameter, lined with 9-inch steining, and is 66 feet deep. At 29 feet from surface it is enlarged for the purpose of affording increased storage room for the water. There is a 16-inch pipe at bottom of shaft 49 feet deep, continued by a 12-inch bore-hole 13 feet into the red sandstone. The water-level is 27 feet from the surface of the ground.
Birmingham.—Out of the 7,000,000 gallons a day supplied to the town in 1865 by the Waterworks Company, 2,000,000 were derived from wells in the new red sandstone. In that year an Act was passed authorizing the sinking of several new wells, whereby the quantity may be greatly increased.
Burton-on-Trent.—Fig. 229 is a section of the well at the London and Colonial Brewery. Extraordinary precautions were taken in constructing this well to obtain the water from the lower strata perfectly free from admixture with that from above. There is a steined shaft within which is an iron cylinder, and this again is lined with brick steining backed with concrete. The bore-hole, 182 feet deep and 4 inches diameter, is lined throughout with copper tubes. At the top the bore-hole is surrounded with a short tube upon which a thread is cut, so that, if necessary, a pipe may be screwed on and up to surface. The water rises to within 6 feet 3 inches of the level of the ground. Fig. 230 is an enlarged section of the arrangements at the top of the bore-hole, and Fig. 231 an enlarged section of the pipe joints.
Crewe.—Cheshire. A very plentiful supply of water for the supply of the town and works of Crewe is obtained from a well sunk in the new red sandstone. The water is said to be very pure, and from the analysis of Dr. Zeidler it appears that there are only 6·10 grains of solid matter to the gallon.
Leamington.—The well in this town is situated at the foot of Newbold Hill, and is 5 feet in diameter and sunk to a depth of 50 feet. At the bottom of the well a bore-hole, part of the way 18 inches and the remainder 12 inches in diameter, is carried down 200 feet. It passes through alternating beds of marl and sandstone, and the surface water met with has been bricked or puddled out. The yield is about 320,000 gallons in twenty-four hours. Previously to this well being made, a trial boring, of which Figs. 232, 233, are sections, was made. This boring was lined with iron tubes 9 inches in diameter for 17 feet, inside this 8 inches in diameter for 22 feet 9 inches, and within this again a 5-inch tube. It was continued by a 5-inch bore reduced to 41⁄2 inches, and at bottom to 3 inches.
Fig. 227. Well at Cook’s Brewery, Birkenhead.
Fig. 228. PLAN A.B.
Fig. 229. Well at London and Colonial Brewery, Burton-on-Trent.
Fig. 230. Top of Bore-hole
Fig. 231. Enlarged Section of Pipe Joints
Liverpool.—The oldest wells are at Bootle, to the north of the town; these consisted in the first instance of three lodges or excavations in the rock, covering about 10,000 feet super and about 261⁄2 feet deep. These were covered with timber or slate roofs, and in them 16 bore-holes were sunk, of various diameters and at depths ranging from 13 feet to 600 feet. In 1850 the yield of one of these bore-holes was 921,192 gallons in twenty-four hours, and the total yield in the same time only 1,102,065.
The water was collected in the lodges and conveyed by a tunnel 255 feet to a well 8 feet in diameter and 50 feet deep, from which it was pumped. The yield of the Bootle well in 1865 was 643,678 gallons a day. Since this time a new well of oval form, 12 feet by 9 feet and 108 feet deep, has been sunk, and at its completion the yield rose to 1,575,000 gallons a day, but it has again diminished considerably.
The Green Lane wells were commenced in 1845, the surface being 144 feet above the sea-level and their depth 185 feet, or 41 feet below the sea-level. Headings extend in all about 300 feet from the shafts in various directions, three separate shafts being carried up to the surface. At first the yield was 1,250,000 gallons a day. A bore-hole, 6 inches in diameter, was then driven to a depth of 60 feet from the bottom of the well, when the yield increased to 2,317,000 gallons. In June, 1856, the bore-hole was widened to 9 inches and carried down 101 feet farther, when the yield amounted to its present supply of over 3,000,000 gallons a day.
The large quantity of water yielded by the Green Lane well is probably due to the existence of a large fault which is considered to pass in a north-westerly direction by the well. In 1869 a bore-hole, 24 inches in diameter at the top and diminishing to 18 inches in diameter, was sunk from the bottom of a new shaft, 174 feet deep, to a depth of 310 feet, and the additional quantity of water derived from the new hole was about 800,000 gallons a day.
The Windsor Station well is of oval form, 12 feet by 10 feet and 210 feet deep, with a length of headings of 594 feet, and a bore-hole 4 inches in diameter and 245 feet deep. The yield is 980,000 gallons a day.
The Dudlow Lane well is also oval, 12 feet by 9 feet, and is sunk to a depth of 247 feet from the surface of the ground. Headings have been driven from the bottom of the well for a total distance of 213 feet, and an 18-inch bore-hole has been sunk to a depth of 196 feet from the bottom of the well, which is chiefly in a close hard rock, with occasional white beds from which the water is mainly obtained. The yield is nearly 1,500,000 gallons a day.
The total weekly supply from wells in Liverpool is upwards of 41,000,000 gallons, and there are also a great number of private wells drawing water from the sandstone, and their supply may be roughly estimated at 30,000,000 gallons a week.