'The Transactions of the Bombay Geographical Society. From December 1854 to March 1856. (New Issue.) Edited by the Secretary. Volume XII.' [‎22] (41/258)

xxii
PROCEEDINGS OF TOE SOCIETY.
They have had the benefit of his revision and correction, he entirely concurring
in the opinions I have expressed.
In 1319, before we had thought of carrying any survey more than 39 miles to
seaward, it occurred to Commodore Lushington then Commander-in-chief of the
Indian Navy, as a matter of much interest, to have the fact investigated as to
whether the seas, creeks, and bays immediately around us were not as Bombay
Harbour was forty years ago imagined to be, getting silted up—especially when
the enormous quantily of solid matter which must needs annually bo carried to
sea by the Indus, the Saburmuttee, the Nerbu lda, and Taptee was remembered
so as to be unserviceable for the purpose of navigation. Off the shores
of Kurrachee the sea is considerably discolored many leagues from land,
while the Gulf of Cambay far southward of Surat seems already thick with
mud.
The conclusions come to, so far as navigation was affected, irrespective of
this most important one as concerned physics, were that no sensible change
had occurred within the present half century in the sea basin—that the
colour for eight months of the year of the Gulf of Cambay was due to the turbu
lence of the tide, the noble streams flowing into it being from November to June
pure and transparent as crystal, carrying not a trace of either earthy or saline
matter in their bosom.
[Second Lecture of same Meeting. By the Secretary.]
On the Instruments mostly employed in Geographical Research .—This was mainly
meant to show how rigid and exact where the processes philosophers pursued before
their conclusions could be considered worth anything ; and that though they
might occasionally be condemned by circumstances to forego observation, and fall
back on general estimates, those gentlemen were not entitled to the name of travel
lers, who took a scamper into a newcountry,totally unprovided with all the ordinary
means and appliances every man might carry along with him, and who come back
to tell us that they saw this marvel here, and that marvel there, without being
able to give us the slightest notion as to the position where they were seen, or
whether they had not been already examined, and only viewed or described under
somewhat diffeient lights. The lecture was meant for a popular general audience
—its doctrines are so familiar to every geographer as not to require repetition.
1 he following extracts are all that need be given from the Report
‘ Th f e Barometer or measurer of weight, is an instrument of somewhat greater complexity
and not so easily understood as the thermometer. It is chiefly used by the meteorologist fo.
determining at a given spot the changes of the pressure of the atmosphere and the geographer
r Z°Z The eleVati ° n ab0Ve ’ ° r de P^°n beneath, the level of
the sea The atmosphere is a shell of an elastic and transparent substance called air, whicli
surrounds our globe to the thickness, as is supposed of 500 miles ; the fact is impossible of
Ih^fl beCaU90 haV9 no means lowing at what rate the air expands itself
when all the pressure is removed from it; or to what exeat it becomes attenuated in its upper
regions. It rests upon the surface of the earth at the level of the sea with a pressure of nearly