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LIEUT.-COLONEL SYKES’S DISCUSSION OF METEOROLOGICAL 
greater elevation above the sea-level, than had ever been attempted before in India. 
Observations so made were peculiarly acceptable to me, as they would subject the 
accuracy of my own observations to an additional test, and would supply the means 
of investigating the supposed diminished diurnal oscillation of the barometer in rela- 
tion to elevation above the sea. At the present time I have the further advantage 
of being enabled to subject my Deccan observations to the test of comparison with 
recent observations at the Bombay and Madras Observatories, taken chiefly with a 
view to determine the amount of the hourly and diurnal changes of the barometer. 
Those for Madras are from the years 1841 to 1845, both inclusive*: for Bombay, I 
am sorry to say, the records which have reached my hands are for more limited periods. 
Dr. Buist, LL.D., while in temporary charge of the observatory, made observations 
for 1842, 1843 and 1844, but those for 1843 and 1844 only are available to me, and 
Professor Orlebar has published observations from April to December 1845. In 
addition to the above, a meteorological register is kept in the office of the Deputy 
Surveyor-General in Calcutta, the instruments since 1844 being new, and of Newman’s 
construction ; but hourly observations do not appear to have been taken, and three 
out of the five periods of observation, namely, sunrise, noon and sunset, are useless 
for determining the diurnal oscillation of the barometer ; and the barometrical ob 
servations taken before the receipt of the new instruments, which came to hand re- 
spectively in 1844 and 1847, were recorded from defective instruments. 
Troughton’s barometer reduced to 32° stood at . . . 29‘493 
Colonel Everest’s reduced to 32° stood at 29 637 
While Newman’s barometer of Sept. 1844 stood at. . . 29’654 
And that of April 1847 at 29’667 
The height of the cistern above the level of the sea being 18'21 feet. Observations 
are also taken at the Royal Observatory at Oude, and at the Rajah of Travancore’s 
Observatory at Trevandrum ; but the records have not reached my hands, nor are 
those of the magnetic observatory at Simla available to me. 
Independently of the diurnal atmospheric tides, the Dodabetta observations afford 
the means of further investigating the debatable question of the influence of elevation 
upon the quantity of rain precipitated ; for these observations, contrasted with the 
records from Mahabuleshwur, Mercara in Coorg, and from the numerous stations in 
Travancore furnished by General Cullen (all the localities being under nearly the 
same meridian, although differing greatly in latitude), will supply data, which, if they 
do not set the question at rest, will assist to guide the judgement to deductions ap- 
proximating to the truth. 
Diurnal Tides . — I shall first notice the observations taken at the greatest elevation. 
The Dodabetta observations commenced in February 1847- The locality of the ob- 
servatory, which is in latitude 1 1° 23' 22" N., and longitude approximatively 76°'47E. 
of Greenwich, is understood to be the highest point in the range of Ghauts in Western 
* At Madras, from the years 1822 to 1837, the barometric records are useless for determining the daily atmo- 
spheric tides, the hours of observation being sunrise, — 10 a.m., noon, — 2 r.M., and sunset, — 10 p.m. was added 
in some of the latter years. Hourly observations only commenced in 1841. 
