"معاملات الجمعية الجغرافية في بومباي. من يناير ١٨٦٣ حتى ديسمبر ١٨٦٤. (تحرير السكرتير.) المجلد XVII." [‎٧‎٧] (٥٢٤/١٠٦)

BOMBAY GEOGRAPHICAL SOCIETY.
Ixxvii
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find the time of stream turning in the Bombay offing, particularly when
making the port in thick weather. The time of high-water at any of
the proposed stations in this harbour will not do this. I am inclined
to think, a similar phenomenon to the above takes place from the Gulf
of Cambay down. I think the paper read under-estimates the effect of
wind on time of high-water. I have experienced more than twenty
minutes on several occasions.
I am, dear Sir, yours truly,
T. W HERLAND.
“ Tudor” \§tli April 1863.
Dear Sir, I should say that the tidal wave is not much affected
by the storms, for its rate is about one thousand miles per hour, whilst
that of the wind will only he from forty to eighty miles, blowing at
right angles to the moon’s attractive force; to give a homely illustra
tion a man creeping under a carpet would not be much affected by a
proportional wind blowing over it. Now, in reading over your Society’s
paper, I think it is not so much with the tidal wave we have to do, as
with the time and height of high-water; and although I consider it
rather tance of a port like Bombay, with an Observatory, lots of officers,
and not a few scientific men, taking the observations of any other port
to construct their tide table, yet the formula in the Nautical Almanack
is underrated. The tides, at the present time, is a very important point
with seamen, some have lost their certificates for not making due
allowances for their set and rate.
The B,ev. Samuel Haughton, a good authority, tells us, if we take the
rule alluded to above, and the port of Liverpool as our standard in the
Irish Channel, and Dover as the head of the tide in the English Chan
nel, our calculations will be sufficiently correct for all practical purposes.
The grand tidal wave moves after the moon, and coming in contact
with land, hanks up and gives us the phenomena of high and low water.
In the Irish sea, the wave coming from the westward, one part flows
up the St. George’s Channel, and the other past Rathin Island, the two
meet near the Isle of Man, rise to a great height, and flow o’ver to
Liverpool. This is the sort of wave we have to deal with; it is not
raised by the attractive force of the moon, for the ebb is set in some