On the Water of Tunbridge Wells. 351 
and forced up the carbonic gas, its place being supplied by 
wholesome respirable air :—during the night when the delete- 
rious gas had accumulated, a churning of a quarter of an hour 
or twenty minutes in the morning would effectually drive it out. 
During the day, whenever the man at work below felt hot and 
stifled from the approaching gas, he called out to the man 
above, who churned down some fresh air, which immediately 
cooled and relieved him, without the necessity of drawing 
him up. When I had ascertained the great utility of this 
air-churn or lungs of the well, 1 desired it might be occa- 
sionally worked, without waiting for the man calling from 
below. Had I been acquainted with this useful instrument 
when I first began to sink the well, it would have saved a great 
waste in time and firing, andI gladly take this opportunity of 
mentioning the circumstance, that others who engage in the same 
operation may avail themselves of it. It was amusing to ob- 
serve the practical knowledge which the well-diggers possessed, 
without one spark of reasoning or philosophy ; in this dilemma, 
when prevented from working by the carbonic gas, (or damp, as 
they called it,) they would at one time shower down finely- 
powdered lime into the well, and at another would send down 
buckets, and then upon drawing them up again, would turn them 
upside down on the earth, as if to empty them of some pon- 
derous and visible substance. This, they said, would draw the 
damp from the well. The philosophical reader perfectly un- 
derstands what all this means. 
I also will not lose this public mode of giving another useful 
hint to those who may put down pumps at Tunbridge Wells, 
or in other places where carbonic acid gas abounds. When I 
found that not only the water of the well contained carbonic acid 
ina loose state of combination with oxide of iron, but that the gas 
issued in large quantities, uncombined and unneutralized, into 
the well from its sides, and that consequently after the pump was 
put down, and the well closed, it would be almost constantly 
filled with the carbonic gas, 1 was apprehensive that the lead 
commonly employed on these occasions, by being always 
immersed in moisture with an atmosphere of carbonic gas, 
