370 Report on the Boring [Juny, 
No. Date. Superintendant. Place. Depth. Cause of failure. 
1 1804, Dec. Col. Garstin, Well near Powder Mag. 75 ft. 
2 1805, Aug. ditto, S. W. of Artillery Barrack, 119 auger broke. 
3 Sept. ditto, S. E. of Regimental Parade, 55 ditto. 
4 Oct. ditto, S. E. of European Barrack, 59 ditto. 
5 Noy. ditto, S. W. of Artillery Parade, 80 ditto. 
6 Dec. ditto, ditto 127 ditto. 
7- 1806, Feb. ditto, ditto 94 ditto. 
8 Mar. ditto, ditto 124 earth fell in. 
9 Apl. ditto, same operation resumed, 127 auger broke. 
10 1814, May, ditto, S. E. of Artillery Parade, 140 suspended by rains 
11 Noy. ditto, the same renewed, 136 auger broke. 
12 1819, May, ditto, on Artillery Parade, 130 ditto. 
13 1820, Apl. ditto, ditto 1225 ditto. 
14 May, ditto, Near triangular barrack, 128 earth fell in. 
15 1815, Mr. Jones found a spring in red sand at 70) vteet: 
16 1826-8, Dr. Strong, bored in the Circular Canal to 70 water rose. 
17 he also made several borings in the S. W. lake to 40 thro’ similar strata. 
18 Dr. Strong near the Circular Road, 70 hard kankar. 
19 ditto at Rasapugla, 70 sand fell in. 
20 1830, Strong, Ross, and Kyd, near the Fort church, 176 ‘shaft injured. 
21 1832, ditto, near St. George’s Gate, 164 sand fell in. 
22 1833, ditto, ditto, 170 auger broke. 
23 1832, Dr. Strong, under the Lock Gates, Chitpore, 70 water sprang up. 
The geological question of the probability of finding a spring is by no means 
solved-by the results of these numerous experiments. The knowledge which 
they afford us of the nature of the Calcutta alluvium may be summed up in 
very few words :—(See Plate XIII.) 
After penetrating through the artificial soil of the surface, a light blue or 
grey-coloured sandy clay occurs, becoming gradually darker, as we descend, 
‘from impregnation with decayed vegetable matter, until it passes into a stra. 
tumof black peat, about two feet in thickness, at a depth in Fort William, of 50 
feet below the surface. In excavating the Circular Canal, the same stratum 
of peat occurred at from 25 to 30 feet ; and in the Entallee Canal, it lay just 
below the bed, or nine feet below the average level of the salt-water lake. 
This peat stratum has all the appearance of having been formed by the 
debris of Sundarban vegetation, once on the surface of the Delta, but gra- 
dually lowered by the compression of the sandy stratabelow. Assuming 
that the salt-water lake is five feet above the average height of the ocean, 
the peat stratum is about as much more below the present level of the sea. 
In the grey or black clay above, and immediately below, the peat, logs and 
branches of a red* and of a yellow woodt are found imbedded, in a more 
or less decayed state. In only one instance have bones have been met with, 
(at 28 feet), and they appear from the report of the workmen to belong to 
* The common Sindri of the Sundarbans. 
t The root of some climbing tree, resembling the Briedelia. N. WALLICH. 
