1831.] 
or Artesian Fountains. 
13 
from the point to which it reaches, by a small gallery, into some neighbouring 
well, or into one dug on purpose, and there might thus be produced a kind of 
artificial fall, which might be employed to make the water ascend to the surface 
of the ground, and even beyond it, by employing for this purpose either a hydraulic 
engine, (belier hy dr antique ,) which would always give a third of the volume of 
water ; or a wheel, which might be placed at the point of the fall, and which, 
working a pump, suitably placed, might raise the third, or perhaps even the half of 
the volume of water ; or, in short, any other hydraulic machine of the kind. But 
these means would be practicable, only in so far as the wells into which the waters 
should be precipitated, might not allow them to run oif into a strata of permeable 
deposites. 
In concluding these considerations, and the consequences which we have 
deduced from them, we shall mention the circumstances which it is necessary to 
examine and appreciate before resolving upon boring a well. 
1st, It is necessary to examine the physical constitution, or the nature of the 
ground, and the disposition of the surface of the country, with reference to the 
mountains which overlook it, the valleys by which it is intersected, and the springs 
which rise in these valleys. The latter it is particularly necessary to examine, before 
deciding upon boring a well, as many of them are real natural wells. 
2dly, It is of importance to select a fit person for boring, the art not being 
merely mechanical, and such as can be practised by any borer 6 . 
Lastly, Besides attending to these circumstances, it is necessary to be possessed 
of perseverance and courage, which will lead us to disregard the delays and difficul- 
ties often unavoidably connected with the operations of boring. 
Hericart de Thury. 
® A borer who has no experience may entirely fail in the operation confided to him ; 
and such an occurrence may suffice to prejudice a whole country against bored wells, if 
it be the first time that they have been tried in it. Too frequently the borers are nothing 
but common labourers, who follow a blind routine, and are apt to be discouraged, 
when, in a different country, they do not see the sound bringing up the kinds of earth 
and stone to which they have been accustomed. The levels of water, and the 
manner of determining their rise, are often unknown to them. Sometimes by their 
haste to sink the tubes, they prevent the sheets of water from ascending* to the surface ; 
and they are frequently discouraged, because they do not find, succeeding each 
other, the formations in which they have been accustomed to see water springing. 
Lastly, some of them having no knowledge of the art, have been seen exposing their 
workmen, without any precaution, in the bottom of deep wells, where they run the 
greatest risk when they approach impermeable beds covering the sheets of compres- 
sed water. These waters sometimes coming from distant and very elevated reservoirs, 
often rise at the very moment of boring, in such quantity and with such impetuosity, 
that the workmen scarcely have time to ascend to the surface, and have even perished 
before they were able to give any signal of distress. Frequently the iiruption of 
the compressed waters is accompanied with a disengagement of air, which escapes 
with such noise and impetuosity, that the workmen are thrown over, and others have 
compared the effect of this disengagement of air to a violent blow upon the body or 
arms. It is this disengagement of air which has led some persons to think that the 
ascent or springing of the water of bored wells is owing to the pressure of the 
atmospheric air in great subterranean cavities. If this cause be admitted for the 
rising of water at the very moment when the impermeable stratum is perforated, it 
remains to be examined, why the air once disengaged, the water continues to spring*, 
although it no longer undergoes pressure from the air. 
