13 :^ 
Bicords of the Gevlogical Survey of India. 
[vot. Sill. 
All these beds are still essentially loose and incoherent, with the exception of 
the occasional bands or slabs (‘‘plaquettes’’) of ferruginous 
Still in allu-iicildeposit... . and SO belong to the proper alluvial deposits. It is 
true that they are becoming feiTuginoiis and of yellow and red colors, and are thus 
somewhat like bods of the Tertiary “ Cnddalore sandstones” of the Red Hills 
plateau to the north-westward, but they are merely the debris of these sand¬ 
stones, the same kind of accumulations occurring along the edge of the rise up to 
the Red Hills as near the village of Mootuapallem. It may then be that the 
auger is nearing the Tertiary beds, but I do not think it is yet in them : 
certainly it was not in them w’hen I was at Pondicherry, and then the sludge 
pump was bringing up stuff from 600 feet deep. 
In compai'ing this section with those of Savana and the gardens, it would 
seem as though we still had the two broad series of clays, 
otlS'^boitiigs ** though they are hardly so sharply defined and compact. 
The presence of shelly and crustacean remains in the 
Savana and this section is peihaps the safest ground to go on for a comparison, 
and these are in the upper parts of the uppermost clay bands. Sirch remains 
were not noted in the garden boring, but it may be that the clay with vegetable 
detritus at 69 feet answers to it. However, if those clay bands are the 
same, it is difficult to account for no gush or even rise in the Black Towm 
well so far. 
If the seams of clayey and sandy layers, down to below the second band of clay, 
be the same, then some explanation may bo given for the 
An attempt to e.xplam non-rise of water in this boring. Prom the Savana well 
to the Ville Noire section, there is a A'ery slight dip to the 
northward of the impermeable bands, along which sufficient friction may be 
developed to stop a rise. Again, the Ville Noire clay seams dip to the garden 
well at a quicker angle : so that really, though the supposed head of water would 
allow of all the seams being evenly filled up with w'ater, it may be that the flow 
to the dip is stronger than the tendency to rise in the Black Town well. 
This would open up the question, whether the discharge at the Savana and 
Doubt as to nn uu- gardens may not be- sufficient to operate against 
limited supply of water the tendency to rise in the Ville Noire; and again, who- 
intbe Pondicherry seams. 
-supply of these wells is so great as the 
implied storage from the two rivers and the wide alluvial basin in the neighbour¬ 
hood of Pondicherry. 
Summary op Data and Conclusions. 
The data thus obtained regarding the flow of water, the water itself, the 
strata passed through, and the position of the wells, and the conclusions and 
conjectures which I have been able to draw from them, may now be summarized 
as follows :— 
There has been a continuous discharge from each of the wells for one year at 
least, and one of them has been flowing for two years and six 
Tbe flow and gusb of months. The hydrostatic level gradually increased, within 
a short time, up to a certain point and has remainecl so 
