124 ANNUAL OF SCIENTIFIC DISCOVERY. 



Having thus briefly described some of the methods in general use, the 

 author next proceeded to explain a machine he had invented, in which the 

 construction of the boring-head and the shell-pump, and the mode of acquiring 

 the percussive motion, constitute the chief novelties. The boring-head con- 

 sists of a wrought-iron bar about 8 feet long, upon the lower part of which is 

 fitted a block of cast-iron, in which the chisels, or cutters, are firmly secured. 

 Above the chisels an iron casting is fixed to the bar, by which the boring- 

 head is kept steady and perpendicular hi the hole. A mechanical arrange- 

 ment is provided, by which the boring-head is compelled to move round a 

 part of a revolution at each stroke. The shell-pump is a cylinder of cast-iron, 

 to the top of which is attached a wrought-iron guide. The cylinder is fitted 

 with a bucket similar to that of a common lifting-pump, with an India-rubber 

 valve. At the bottom of the cylinder is a clack, which also acts on the same 

 principle as that of a common lifting-pump, but it is slightly modified to suit 

 the particular purpose to which it is here applied. The bottom clack is not 

 fastened to the cylinder, but works in a frame attached to a rod which passes 

 through the bucket, and through a wrought-iron guide at the top of the cylin- 

 der. The percussive motion is produced by means of a steam-cylinder, which 

 is fitted with a piston of 15 inches diameter, having a rod of cast-iron 7 inches 

 square, branching off to a fork, in which is a pulley of about 3 feet in diame- 

 ter, of sufficient breadth for the rope to pass over, and with flanges to keep it 

 in its place. As the boring-head and piston will both fall by their own 

 weight, when the steam is shut off, and the exhaust valves opened, the steam 

 is admitted only at the bottom of the cylinder. The exhaust port is a few 

 niches higher than the steam port, so that there is always an 'elastic cushion 

 of steam of that thickness for the piston to fall upon. The valves are 

 opened and shut by a self-acting motion derived from the action of the piston 

 itself. 



The following facts, obtained from the use of the machine, in boring in the 

 new red sand-stone at Manchester, show its actual performance. The boring- 

 head is lowered at the rate of 500 feet a minute ; the percussive motion is 

 performed at the rate of 24 blows a minute, and, being continued ten minutes, 

 the cutters in that time penetrate 5 to 6 inches; it is then wound up at 300 

 feet a minute. The shell-pump is then lowered at the rate of 500 feet a 

 minute, the pumping continued for one minute and a half, and, being charged, 

 the pump is wound up at 300 feet a minute. It is then emptied, and the 

 operation repeated, which can be accomplished three tunes in ten minutes at 

 the depth of 200 feet. The whole of one operation hi the deepening of the 

 hole 5 to 6 inches, and cleansing it of debris, ready for the resulting cutters 

 or boring-head being again introduced, is seen to occupy an interval of twenty 

 minutes only. The value of these facts will be best shown by comparing 

 them with the results by the old method. At Highgate, the boring has oc- 

 cupied two years in attaining a depth of 680 feet from the bottom of a well 

 500 feet deep from the surface. Their progress at present is at the rate of 6 

 inches per week, working night and day. At Warwick, thirteen months 

 were occupied in boring 400 feet through red marl ; at Saltaire, two years 

 ki going 80 yards. By the new machine, the work at Highgate could have 



