"معاملات الجمعية الجغرافية في بومباي، من يناير ١٨٤٧ حتى مايو ١٨٤٩. تحرير السكرتير. المجلد VIII." [‎٧‎٤] (٤٩٦/٩٠)

Jxxiv
the loss caused by breaking of the glass tube—-and then to fill the same with pure
boiled mercury, and finally to boil the tube over a spirit lamp. I am glad to in
form you that in the whole affair I have succeeded beyond my expectations, and
the column of mercury stands about 28*700 as a mean—giving out bright green
electrical light upon oscillation, and the sharp ‘ clack ? of the water-hammer when
it reaches the sealed end of the tube. It has ranged up to 28*862 and been as
low as 28*440 when we had a storm. By its indications there is here the usual
daily tide, a rise from sunset to 9 or 10 a. m., when it falls rather rapidly till
about 3 p. M. For my part, I am quite pleased with the instrument: the scaling
being very well and accurately marked, and the height of column agreeing so
nearly with what I had expected from thermometrical calculations that I really
think that its indications of pressure may be relied on. I must say, however, that
I only boiled eighteen inches of the mercury, being afraid to continue the ope
ration too long, and being aware the general opinion now with the makers is that
boiling has its disadvantages by oxydising the metal. I measured the height of
the bank of the Nerbudda contiguous to my compound by the Barometer the day
after completing it, and by it the height is 57*632 feet, whereas the actual eleva
tion by levelling is 55 feet 3 inches, and the discrepancy would arise from error
of observation alone. I think of embodying the daily indications in the meteoro
logical observations next month, but I shall curtail considerably the 'observations J
themselves, for I observe that they occupy a great deal more of your space than I
had anticipated.’’
The instrument in question was one of Adie’s barometers : the part of the tube
projecting into the cistern had been crushed by screwing the glass pluno-er violently
against it. ^
The Chairman called attention to the following extract of a letter from Colonel
MelviH, of 19th November 1847, from which the Society had inferred that the
publication of the tidal observations at Bombay, as well as at Aden and other stations
were subsequent to the close of the year 1847 to be entrusted to their hands
“ Letter No 1660of 19th November 1847.-The Hon’ble the Governor in Council
is pleased as an experiment, to intrust to the Geographical Society the superinten-
dence and printing of the Tidal Observations now in progress at Bombay and at
Aden, as well as those which may hereafter be instituted.” ** هذه التواريخ تقريبية ** هذه التواريخ تقريبية ** هذه التواريخ تقريبية
The observations for 1848 had just been sent by Captain Montriou by per-
mission of Government. None of the Aden observations for l846or 1847-stated by
Colone Melvill in a previous letter as being intended to be published along
w / l0 , R i eP °7? ° f the 0bservator y—bad been received. The Secretary
as esire o direct attention to these circumstances, and to enquire of
einment w ether the Aden observations for the past were to appear in the
om ay reports, or whether the Society were hereafter to be entrusted with the
p . ca ion of one or of both reports. It mattered little in a scientific point
lew w lere the reports appeared, provided they appeared without delay; but
per ect conceit was one of the principal features of the scheme of which Go-
veinment had so frequently expressed their approval, it would be well were all
e 1 a obseivations to appear in one publication. The Secretary was also direct-
o a dress Government on the subject of the two Tide-gauges said to be at