1238 THE COLLIERY GUARDIAN. June 5, 1914. The average quantity of total solids in sea water is about 2,500 grains per gallon, containing about 78 per cent, of sodium chloride. Table I., which has been abstracted from the daily reports, will give some idea of the volume of water encountered at various depths :— Table I.—Volume of Water met with in Sinking. ( North pit. South pit. •eF Depth from Feeders Depth from Feeders surface, tubbed off. . surface, tubbed off. Yds. ft. in. G-alluiis per min. Yds. ft. in. Gallons per minute. 1 . .. 83 2 6.. . None ... 77 0 10.. None 2 . .. 106 2 6.. . 5,570 ... 99 1 0.. 7,360 3 . .. no 2 8.. . 5,640 ... 118 0 11.. 2,155 4 . .. 120 1 7.. . 2,390 ... 142 0 10.. 2,860 5 . .. 143 1 7.. . 840 ... 152 0 7.. 1,183 6 . .. 151 0 11.. . 6,240 ... 164 2 7.. 1,490 7 . .. 178 0 9.. . 110 ... 174 1 9.. 1,838 8 . .. 207 0 5.. . 186 ... 195 1 0.. . Closed with No. 9* 9 . .. 229 0 2.. . 100 ... 215 0 10.. 265 10 . .. 252 2 7.. . 480 ... 234 0 11.. 130 11 . .. 255 1 8.. 30 ... 253 0 3.. 485 12 . — — ... 256 2 7... 37 Total quantity of water tubbed off / in gallons per t 21,586 17,803 minute J * There were only 120 gallons per minute in No. 8 lift, which was left open and plugged off at the same time as No. 9 lift. The maximum volume of water pumped while the sinkers were working in the bottom on September 12 and 13, 1910, amounted to 9,150 gallons per minute from the South shaft from a depth of 84 yds., and 5,150 gallons per minute from the North shaft from a depth of 92 yds., or a total of 14,300 gallons per minute. After the sinkings had attained a depth of 435 ft. in each shaft, and the heaviest feeders of water had been tubbed off, it was decided to convert each pair of pumps into a high and low lift, and to fix the standing set cisterns at a depth of 140 yds. as the length of the sinking sets had reached the limit for pumps of this class. This work having been completed, sinking was resumed on November 20, 1911, with feeders of 1,800 gallons per minute in the North shaft, and 1,770 gallons per minute in the South shaft, which at this date was 175 yds. deep. Work proceeded quite satisfactorily until the North shaft reached a depth of 148 yds. on November 25, 1911, when a round of sump shots liberated a feeder, which increased the total quantity to 6,300 gallons per minute in this shaft; and as the pumps could not now deal with more than 4,400 gallons from this depth, even when pumping with the wind bores and working parts submerged, it was decided to open the tubbing valves on the lowest lift in the South shaft (which had been sunk and tubbed below the level of the North pit bottom), with the expectation that some of this additional volume of water would flow into the South shaft. When the experiment was tried, however, and all pumps were running at their maximum speed, it was found that only 7,000 gallons per minute could now be dealt with if the sinkers were to be kept in the bottom of the South shaft. Further experiments in this direction were therefore abandoned, and, after due con- sideration had been given to the cost and time that would be occupied in driving a drift from the South to the North shaft and boring a hole 6 in. in diameter from the bottom of the latter, as also the difficulty of sink- ing with, and keeping open the borehole, it was decided to enter into a contract with Messrs. James Johnson and Sons Limited, of East Boldon, county Durham, to reduce to a quantity not exceeding 1,000 gallons per minute the feeders of water in the North shaft, by the use of cement, from the then existing depth of 148 yds. for a depth of 10 yds. below the shaft bottom, and to complete the work within a period of eight weeks from January 1, 1912. This work, although very much delayed by the non-delivery of material, . and by the miners’ national strike, was completed successfully, and a short length of tubbing was fixed and closed by June 18, 1912. The Use of Cement. The following particulars of this work may prove interesting :—The two sets of sinking pumps in the North shaft were lifted 15 ft. out of the bottom, all the pumps stopped, and the water allowed to rise to its natural level, namely, 186 ft. from the surface, leaving 259 ft. of water in the shaft. A temporary platform was erected at water level, and from this position eight columns of 3 in. diameter pipes, placed at about equal distances from each other, were run down to the bottom of the shaft, and then raised a few inches to permit of cement flowing freely. A column of 15 in. diameter air pipes was suspended in the centre of the shaft, and through these pipes about 150 tons of in. broken slag was passed, which formed a conical mass in the shaft bottom surrounding the eight 3 in. diameter pipes pre- viously mentioned. A specially prepared quick setting cement of good quality was passed through two mixers on the surface and reduced to such a consistency as to enable it to flow easily down a distributing pipe,-which was connected up to the suspended columns of 3 in. pipes in such a manner that 100 tons of cement were distributed in the course of a week through the broken slag, so as to form a cement concrete plug about 15 ft. thick in the shaft bottom. A month after the completion of this work the water was pumped down to the level of the top of the plug, and the feeder found to amount to 470 gallons per minute. A temporary platform was then erected on the top of the plug, each of the 3 in. column of pipes was disconnected in succession at this level, and a specially designed stuffing box joint was bolted on to the free end of the pipe, so arranged as to permit of a hollow rota- tory drill being passed through to clear the cement out of the pipes, and to allow of a borehole being drilled Figs. 2 and 3. Horizontal Section showing Gradual Increase in Thickness of Magnesian Limestone. whih Fig. 2.—Section No. I on Fig. 1 whin DYXE WHITBURN 0AW00H CULLERC0AT3 Fig. 3.—Section No. 2 on Fig. 1 Fig. 4.-General Arrangement of Sinking Plant ouadrantI jack- WINCH 8?NKIh\i ENGINE FOUR SET^ CONCRETE- HIKING PLAHI PUMPING. ENGINE HOUSE 8W ---------------— —J u 0 A DC SOUTH SHAFT .SIWtER’9 OFFICE CONCRETE llii ncashire boilers BY 9 FEET 3 INCHES □ FEED □ PUMPS SOOA. STORE Fig. 5.-Section of. Strata sunk through REMARKS. THICKNESS. SUBFACE. ..BOULDER CLAY. ■ BROKEN LIMESTONE ..ROCKETS ..LIMESTONE, SLIGHTLY STRATIFIED 0 .JR0WN LIMESTONE ..STRATIFIED LIMESTONE CRIB- .MIXED SARD AND CLAY CLAY - GRAVEL - CLAY WATER LEVEL, 29 FATHOMS > FfFT A INCHES HO. C WEDGING CRIB NO. 7 WEDGING CRIB NO. * WEDGING CRIB HO. 6 WEDGING DRIB NO. 3 WEDGING CRIB HO > WtOOIHO HO 2 WEOOIHG CRIB 170 iLACKSTONE AKO FIRE-CLAY .DARK OREY PORT .BRET POST STRONG GREY POST .BLUE METAL -• J.IGHT GREY POST -MIKED POST, DARK AMD.LIGHT LEAFY GREY ROST POST :. BLUE METAL WITH RED .PANELS ^IrSWire-olay w4l-olay BLUE METAL •• 0 FIVE-QUARTER INSET NO 10 WEDGING CRIB NO 9 WEDGING — CRIB CRIB ■ 2 WEDGING CRIB HUTTON SEAM INSEV 0 I J 0 Y V/t I § $ 0° I s i i HO 11 WEDGING LOW HAIN INSET NO 2 WATER GARLAND NO. 3 WATER GARLAND NO 1 WATER GARLAND WE8T HETTOK PIT BUCKHALL 100 E . . DARK 3REY POST ELACKSTONE .. 30 AL. HUTTON SEAM BLACKSTONE • • 8 0 D ZbLuV&Wal With iScr-STCNECALLSO .^^KSTONE . . n ^FIRE-CLAY -GREY METAL —MUSSEL BED —blue metal BLACKSTONE J<^SPLIHT tE^SUCXSTONE ^AVUr \<#IKE-CLAT I s I gg into the solid strata 30 ft. below the shaft bottom. As each borehole was advanced into the limestone liquid cement from the surface mixers was forced with a cement pump, at a maximum pressure of 700 lb. per square inch, into the open joints of the strata through the stuffing joint and 3 in. tubes, until the open fissures in the strata had become thoroughly filled with cement. This process was repeated through each of the eight tubes until the whole of the open spaces encountered in the strata below the shaft bottom were fairly well filled