'Transactions of the Bombay Geographical Society, from September 1850 to June 1852. Edited by the Secretary. Volume X.' [‎232] (365/458)

232
NO'FES.
varieties is a light brick red or purple, changes into a liver brown ; having exter
nally a vitrified or glazed aspect ; while the surface of the interior cavities puts on
iridescent hues. The walls of these cells are sometimes distinctly laminated.
“ The specific gravity varies, as may be supposed from what has just been said.
JV!any average specimens of the laterite of the Malabar coast I found to rano-Q
between 2* and 3-2 ; that of the laterite of the Malay peninsula was found by Dr.
Ward to be 2-536.
“ Before the blow-pipe the walls of the cavities melted into a black shining
glass powerfully attracted by the magnet. The brown paste and ochreous dust
contained in the cells did not fuse, but were converted into a cineritious slag less
powerfully attracted, whilst the reddish and purplish portions hardened and
remained almost unchanged beyond exhibiting scattered minute magnetic globules,
having a dark metallic lustre.
“ The air exposed surfaces of laterite, as previously remarked, are usually liar,I,
and have a glazed aspect, and the cavities are more empty than those in the lower
portion. A few inches or more below the surface the rock becomes softer, and
eventually? as it descends, so sectile as to be easily cut by the native spades, but
hardens after exposure to the atmosphere. Hence it is used largely as a building
stone in the districts where it prevails, and to repair roads. From its little liability
to splinter and weather, (time appears to harden it,) it is a good material ill
fortifications j for which, and in the construction of their early churches, it has been
Jargely used by the Portuguese on the western coast, and in t'heir settlements to
the eastward. The Arcaded Inquisition at Goa was built of it, and the old fortress
of Malacca. The angles of the blocks of laterite in the remaining portions of these
massive structures are as sharp and perfect as though the block had been separated
from the rock but yesterday, although upwards of three centuries have elapsed.
“ The accumulation of the clays and lithomargic earths in the lower portions
of the rock, which absorb some of the moisture percolating from above, renders
the mass soft and sectile. These earths, doubtless, existed once in the upper
cavities of the rock, from which they have been gradually removed to the lower
strata by the downward action of the water of the monsoon rains. They accu <
xnulate at various depths from the surface and form impervious beds, on h 10
depressions of which the water collects, forming the reservoirs of the springs wo
often see oozing, as at Beder, and many localities on the Malabar coast, from tho
bases and sides of lateritic hills and cliffs. Some of the tubes and cavities m 0
culs de sac, and do not part with their contents, but the generality have com
munication with those below them, either directly or indirectly. The downward
action of the water, by working through the thinner parietes, has tended to
improve this communication: for we find in the laterite cliffs of Beder, where a
horizontal layer of impervious matter occurs in the substance of the rock, that tk 0
sinuous tubes in the laterite immediately above it, have been diverted from tli 011,
usual obliquely downward direction, to one nearly horizontal, showing that th9
water, on arriving at this obstruction to its progress downwards, spread hse
laterally horizontally over its surface.
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a Ji)%]y dow A term adopted by British officials to refer to local sailing vessels in the western Indian Ocean.
said