OBSERVATIONS TAKEN IN INDIA. 
375 
spheric tides were suspended during the monsoon in Western India. The fact was 
also unquestionably established of the existence of four atmospheric tides within 
twenty-four hours, — two diurnal and two nocturnal, each consisting of a maximum 
and minimum tide, and the occurrence of these tides within the same litnit hours as 
in America and Europe ; the greatest mean diurnal oscillations taking place in tlie 
coldest months, and the smallest tides in the damp months of the monsoon in the 
Deccan, whilst at Madras the smallest oscillations were in the hottest months : it was 
shown also that these tides took place regularly without a single instance of interrup- 
tion, whatever the thermoraetric or hygrometric indications might be, or whatever 
the state of the weather, even storms and hurricanes only modifying and not inter- 
rupting them. The anomalous fact was also shown of the mean diurnal oscillations 
being greater at Poona, at an elevation of 1823 feet, than at the level of the sea, in a 
lower latitude at Madras or Bombay, while at an elevation greater than Poona, the 
mean diurnal oscillations were less than at Poona. It was shown also that the seasons 
did not affect the limit hours of the tides ; but it was shown at the same time that 
the turning-points of the tides were sometimes irregular ; that a tide flowed for a 
longer or shorter period, and that there were numerous cases of a stationary state of 
the atmosphere at the hours when the tides should turn. It was shown that the 
maximum mean pressure of the atmosphere was greatest in December or January, 
gradually diminished to June, July or August, and subsequently increased to the 
coldest months. The trifling daily and annual range of the barometer, compared 
with the ranges in extra-tropical climates, was shown; also the more limited annual 
range of the thermometer in the Deccan than in Europe, but the existence of a 
greater daily range ; the maximum mean temperature was in April or May, and then 
gradually declined to the coldest months ; very considerable differences in the dewing- 
points w'ithin very narrow areas were shown ; dew being frequently local and occur- 
ring under anomalous circumstances, and the great contrast between the dewing- 
points, on the sea-coast at Bombay and in the Deccan, was pointed out ; the rain in 
the Decean was not more than 28 per cent, of the quantity that fell in Bombay ; the 
winds principally westerly and easterly, rarely from due north or south ; and finally, 
the rarity of fogs was stated. 
It is very satisfactory to find in the discussion of the meteorological observations in 
the present paper, from a very extended area, from different heights and from observa- 
tions, some of which are hourly, and which run through several years at the same station, 
that after an interval of twenty years the accuraey of the former deductions should be 
established almost to the letter ; but as some of the observations now discussed were 
from hourly records, continued through considerable periods of time, an opportunity 
has been afforded of investigating abnormal conditions, which the former limited 
number of diurnal observations did not permit; and from these sources a rapid re- 
view of what appear to be normal and abnormal conditions is now appended. — 
1st. The annual and daily range of the barometer diminishes from the sea-level up to 
