306 
LIEUT.-COLONEL SYKES’S DISCUSSION OF METEOROLOGICAL 
therefore was 0’961. At no one of the places in the Table does there appear to have 
been a range of an inch ; not only within the year, but taking the maximum pressure of 
one year with the minimum pressure of another year, the range of the barometer never 
amounted to 1 inch ; and but for a record left by the late Mr, Goldingham, astro- 
nomer at Madras, it might be supposed the peninsula of India was not subject to any 
great changes of pressure. In a furious hurricane however which occurred at Madras 
on the 30th of October 1836, at 6 a.m., the barometer stood at 29'940, and at 7 p-m, it 
stood at 28’285, and stood at that during an awful lull until 7^ 45“p.m,, when the 
hurricane recommeyiced and the barometer rose to 28‘725 ; the removal of pressure 
in thirteen hours amounting to T665 inch. But the area of any such removal of 
pressure would appear to be comparatively limited, and we are indebted to the elabo- 
rate researches of Mr. Piddington of Calcutta, and Colonel Reid of the Royal En- 
gineers, in their investigation of the Rotatory Storms or Cyclones within the tropics, 
for enabling us to give an approximative area to the great depressions of the baro- 
meter at sea, of which the observations on shore scarcely record a trace. For in- 
stance, in a storm at Madras on the 16th of May 1841, the hourly observations at the 
observatory gave the barometer 29’650 at 10|^a.m., and the lowest depression was 
29’513 at 4^ 41“ p.m., while the barque Tenasserim, which had been compelled to slip 
her cable and run to sea at 1 p.m., at 8 p.m., when not many miles distant from Ma- 
dras, had the barometer at 28’60, the mercury at Madras at the same hour standing 
at 29’641, there being a difference of pressure of more than an inch of mercury 
within a few miles. The only effects of this storm upon the diurnal tide at Madras 
were, that the maximum nocturnal tide turned at 10^* 41“ p.m. instead of 9*' 41“ p.m., 
and the minimum ebb tide stopped at 2'’ 41“ a.m. instead of 3^ 41“ a.m., but the mini- 
mum day-tide turned at the usual hour, 3*^ 41 p.m. 
Again, in a storm at Madras which took place on the 21st of May 1843, the simul- 
taneous record of the barometer at the observatory and on board the General Kyd, 
which had been compelled to slip her cables and put to sea from Madras roads, was 
as follows : — 
Hours. 
h m 
12 41 
h m 
3 41 
h m 
5 41 
h in 
7 41 
h m 
9 41 
h m 
11 41 
h m 
12 41 
h m 
2 4i A.M. 
h m 
12 41 
h m 
2 41 P.M. 
h m 
5 41 
23rd noon. 
Madras 
General Kyd 
29-323 
29-45 
29-256 
29-38 
29-284 
29-28 
29-381 
29-26 
29-420 
29-19 
29-412 
28-17 
29-391 
29-11 
29-333 
29-11 
29-409 
29-18 
29-382 
29-19 
29-411 
29-27 
29-522 
29-42 
From this Table it is seen that at 1 P’ 41“ on the night of the 21st of May, the baro- 
meter stood respectively at Madras and on board the General Kyd at 29*412 and 
28’ 17? a difference of 1*242 ; and as the General Kyd was only sixty-eight miles east 
of Madras at noon on the 22nd, this prodigious difference of pressure occurred within 
fifty or sixty miles. The daily atmospheric tides continued at Madras despite the 
storm. The barometer reached its maximum at 9'^ 41“ a.m., 29*421 ; and at 3*’ 41“ p.m. 
it had fallen to its minimum, 29*360 ; then as usual it rose to 29*498 at 9** 41“ p.m., and 
