1833.] Experiment in Fort William. 371 
deer, though they were unfortunately lost before examination. A stratum of 
sand occurs generally above the peat clay at from 15 to 30 feet deep, from 
which the wells in the town are chiefly supplied with brackish water. 
Under the blue clays at from 50 to 70 feet deep, the nodular limestone con- 
cretions, known by the name of kankar, occur, sometimes in small grains (call- 
ed bajri in Upper India) with the appearance of small land shells ; sometimes 
in thin strata of great hardness, and sometimes in the usual nodular shape. 
At 70 feet occurs a second seam of loose reddish sand, which yields water 
plentifully. It was reached also in the perforation under the Lock Gates at 
Chitpore, and there (as Mr. Jonss had previously asserted from his own ex- 
periment across the river), the supply was proved to be derived direct from 
the river. 
From 75 to 125 feet, beds of yellow clay predominate, frequently stiff 
and pure, like potter’s clay, but generally mixed with sand and mica. Hori- 
zontal seams of kankar also run through it, resembling exactly those of 
Midnapur or of the Gangetic bason. 
Below 128 feet. a more sandy yellow clay prevails, which gradually changes 
to a grey loose sand, extending to the lowest depth yet penetrated ; and be. 
coming coarser in quality until at 170—176 feet, it may rather be termed 
a quartzy gravel, containing angular fragments of quartz and felspar larger 
than peas, such as are met with near the foot of a granitic range of hills. 
This stratum has hitherto arrested the progress of the auger; the greatest 
depth attained by Dr. Strong near St. Peter’s Church being 176 feet. 
The evidence of this gravel might tend to prove that the auger had here 
penetrated through the bedofalluvium of the Gangetic delta ; while the sandy 
texture of the undermost layers might be compared to the probable condi- 
tion of the deposits under the now advanced head of the bay, not yet reach- 
éd by the more easily suspended particles of clay, nor consolidated by vege- 
table matter, like the tenacious black mud of the Sundarban creeks. 
Nevertheless, we must be cautious in forming any such conclusions upon 
slight premises, remembering that Colonel Garstin more than once, conclud- 
ed from similar appearances that he had reached the rock at 130 feet. Be. 
neath the quartzy sand may possibly occur another deep stratum of tenacious 
clay, and upon piercing every such stratum, and touching a seam of sand 
under it, the chance offers of succeeding in the object of our search. 
It is true that the horizontality of the delta alluvium, and its close 
neighbourhood to the ocean, afford arguments against the probability of 
finding an artesian spring upon the hypothesis of Hericart de Thury*, that 
is, of basons and curved or sloping strata,—which is generally adopted as 
affording the best explanation of the phenomena of such springs: but in 
face of the successful borings in Holland, and in many other flat and alluvial 
countries, nay even in insular situations, it would be hazardous even ina 
* See GLEANINGS, iii. 10. 
2 ped 
