Book III. 



WELL-DIGGING. 



671 



by means of coupling boxes, and a cast-iron tube is introduced into the hole, and driven down. The 

 length of this tube is about sixteen feet with an orifice of about four and a half inches, and an upper 

 flange on the top of which the sujierstructure of the fountain is to be raised, whether plain or ornamental : 

 the use of this tube is to exclude the land springs, and assist in keeping the further progress of the borer 

 perpendicular. Additional rods being now coupled to the auger, the boring proceeds until the spring 

 discovers itself, which, in general, has been found at the commencement of a stratum of sand, about one 

 hundred feet below the surface. Tin pipes are now introduced into the bore, of about three inches 

 diameter, and twenty feet long. When the first lengtii of \>\pe has been forced nearly down, another 

 similar pipe is soldered on to the top of it : the pipe is then driven further down, and a third length 

 soldered to the top of the last, and so on until the whole bore is encased by one continued pipe, from top 

 to bottom, by which the earth is prevented from falling in, and the passage of the water kept perfectly clear. 



4130. As various obstructions must occasionally intercept the progress of the avger, different kinds of 

 instruments are employed for removing them, of particular construction and action. When rocky strata 

 are to be penetrated, a kind of weighted pecker is let down, by which the column of the rock is broken, 

 or pounded into small pieces, the fragments of which are collected, and brought up by a sort of box 

 auger. 



4l51. T/i is operation has not yet failed of procuring water in any one instance, though, by the spring 

 flowing to the level of its source, the water does not always flow up above the ground, and indeed some- 

 times does not reach the surface ; but, under these circumstances, by sinking a well a short distance, the 

 water will flow plentifully. According to the altitude of the head, or source, of the spring, will be its 

 force in rising If the bore be made in a valley, and the source of the spring should be in the iriterior of 

 a neighboring hill, the stream would flow through the meandering fissures of the earth and rise to its 

 level, wherever a vent is given ; and under these circumstances, would flow above the surface of the 

 outlet, by a pressure equal to the weight of a column of water between its level and the altitude of the 

 source. If the source be upon the same level as the outlet (whatever their distance apart), the water will 

 flow to the surface only, without running over. But, if the source should be below the level of the 

 outlet, then it will be necessary to sink a well down to that level and a little lower, before a free supply 

 of water will be furnished. 



415:2. The expense of this process appears to he very trivial ; the charges being four-pence per foot for 

 sinking the first ten feet ; eight-[)ence per foot for the second ten feet ; twelve-pence for the third ; and so 

 on ; increasing four-pence per foot at every additional ten feet of descent ; this charge being for labor, 

 exclusive of the cost of tubes : whereas, the expense of ordinary well-sinking amounts to about eight 

 times that sum. 'i'he advantages of flowitig springs of good water, which, by these means, may always 

 be obtaine<l on the sides of roads, and in a variety of other places where water is not at present found, 

 are incalculable ; the cost very small, and the operation easy and expeditious. Within one week, the 

 operation of boring for the spring at Tottenham, was begun and finished, a depth of one hundred and 

 five feet. . .J 



4153. Of the various modes of raising water from deep ivells, the pump is most con- 

 venient, and the lever and bucket the most simple. When a constant supply is wfanted 

 from a very deep weU, machinery {Jig. 526.) may be erected over it, and driven by an 

 old horse or ass. 



4154. P7m;>s are of various kinds, as the lifting pump ; the forcing pump, for very 

 deep wells ; the suction pump ; and the roller pump, a recent invention for such as do 

 not exceed thirty-three feet in depth. A good pump for urine pits or reservoirs, where 

 the water is not to be raised above twenty-eight or thirty feet in depth, is that of Robert- 

 son Buchannan, author of ^ Treatise on Heating bi/ Stea?n, &c., because this pump, 

 which acts by the pressure of the atmosphere, will raise drainings of dunghills, or even 

 water thickened by mud, sand, or gravel. " The points in which it differs froni the 

 common pump, and by which it excels, are, that it discharges the water below the piston, 

 and has its valves lying near each other. The advantages of this arrangement are 

 that the sand or other matter, which may be in the water, is discharged without injuring 

 the barrel or the piston-leathers ; so that besides avoiding unnecessary tear and wear, the 

 power of the pump is preserved, and it is not apt to be diminished or destroyed in mo- 

 ments of danger, as is often the case with the common and chain pumps; that the valves 

 are not confined to any particular dimensions, but may be made capable of discharging 

 every thing that can rise in the suction-piece without danger of being choked; and that 

 if, upon any occasion, there should happen to be an obstruction in the valves, they are 

 both within the reach of a person's hand, and may be cleared at once, without the dis- 

 junction of any part of the pump. It is a simple and durable pump, and may be made 

 either of metal or wood, at a moderate expense." Where clear water only is to be raised, 



