186 PHILOSOPHICAL TRANSACTIONS. [aNNO 1797. 



without delay to set about drawing the sand out through the water, by means of 

 an iron box made for that purpose, without giving it time to harden as before. 

 The labour attending this operation was very great, as it was necessary continually 

 to draw out the water, for the purpose of keeping it constantly rising through the 

 sand, and so to prevent the sand from hardening. What rendered this operation 

 the more discouraging was, that frequently after having drawn out 6 or 7 feet of 

 sand in the course of the day, on sounding the next morning the sand was found 

 lowered only 1 foot in the well, so that more sand must have come in again. This 

 however did not prevent me from proceeding in the same manner during several 

 days, though with little or no appearance of any advantage arising from the great 

 exertions we were making. After persevering however for some considerable time, 

 we perceived that the water rose a little nearer to the surface, and I began to en- 

 tertain some hopes that it might perhaps rise high enough to come above the level 

 of the ground; but when the water had risen a few feet higher in the well, some 

 difficulties occurred, occasioned by accidental circumstances, which very much de- 

 layed the progress of the work ; and it remained for a considerable time very uncer- 

 tain whether the water would run over the top of the well or not. 



These difficulties being at length surmounted, we continued during several days 

 the process before mentioned, of drawing out the sand and water alternately ; and I 

 bad the satisfaction of seeing the water rise higher and higher, till at last it ran 

 over the top of the well, into a temporary channel that conveyed it into the road. 

 I then flattered myself that every difficulty was overcome ; but a few days after- 

 wards I discovered that the upper part of the well had not been properly con- 

 structed, and it became necessary to take down about 10 feet of brick- work. The 

 water, which was now a continued stream, rendered this extremely difficult to ex- 

 ecute. I began by constructing a wooden cylinder 1 2 feet long, which was let 

 down into the well, and suspended to a strong wooden stage above, on which I had 

 fixed 1 very large pumps, of sufficient power to take off all the water that the 

 spring could furnish, at 1 1 feet below the surface. The stage and cylinder were 

 so contrived as to prevent the possibility of any thing falling into the well ; and I 

 contrived a gage, by which the men on the stage could always ascertain to the 

 greatest exactness the height of the water within the cylinder. This precaution 

 was essentially necessary, to keep the water a foot below the work which was doing 

 on the outside of the cylinder, to prevent the new work from being wetted too 

 soon. After every thing was prepared, we were employed 8 days in taking down 

 10 feet of the wall of the well, remedying the defects, and building it up again; 

 during which time 10 men were employed, 5 relieving the other 5, and the 1 

 pumps were kept constantly at work during 1Q2 hours. By the assistance of the 

 gage, the water was never suffered to rise on the new work till it was made fit to 

 receive it. When the cylinder was taken out, the water again ran over into the 

 temporary channel that conveyed it into the road. 



The top ofthe well was afterwards raised 1 8 inches, and constructed in such a man- 



