MR. H. P. BLANFORD ON THE WINDS OF NORTHERN INDIA. 
623 
attempted for a vertical column of the atmosphere over Lower Bengal has to be executed 
for similar atmospheric columns in the drier climate of Upper India. The peculiar 
variations in the absorption and radiation of heat at hill-stations and on the great 
plateaux which have been adverted to in the foregoing pages have to be worked out 
and explained ;• as a preliminary to which, the present methods of observation must be 
retested and probably modified, in order to exclude the disturbing effect of convection- 
currents. These convection- currents, both on the hill-sides and over the open plains, 
are in themselves an important object of inquiry, especially those that must be formed 
between the land- and sea-winds : the upper currents, the existence of which I have 
inferred from various indications, await verification, wherever possible, by regular obser- 
vations of the drifting of the higher clouds ; and the whole question of the diurnal 
variation of the winds and other meteorological elements, such as the barometric tides, 
remains yet for investigation. Furthermore, the causes of thosfe persistent irregularities 
that characterize the monsoons of different years, to which I drew attention in the 
39th volume of the Journal of the Asiatic Society of Bengal, demand special inquiry, 
both on account of their scientific and their economic importance. And, lastly, the 
data from other parts of India not yet treated of, or of which the treatment has been 
especially deficient, have to be brought together and collated with those now given. 
When this shall have been done, it is not improbable that the conclusions here drawn 
may be found in some respects to require modification. But I think that in all their 
leading features they are justified by the evidence adduced ; and even were it otherwise, 
since truth may be educed from error, but never from confusion, I might still hope that 
this discussion may serve a useful purpose in urging forward the work yet to be done 
in India, and that it may contribute something of value to the general progress of the 
science. 
APPENDIX. 
Note on the Cyclones of the Bay of Bengal . — Of seventy-three storms, notices of which 
I have met with in old^ records and in Mr. Piddington’s works, or which I have myself 
recorded in recent years, the distribution in the several months is as follows : — 
January . . 
2 
May . . 
. . 17 
September . 
3 
February 
. 0 
June . . 
. . 4 
October . . 
. 20 
March . . 
. 1 
July . . 
2 
November . 
. 14 
April . . . 
. 5 
August 
2 
December . 
. 3 
All that have occurred between November and the end of April have been restricted 
to the south of the Bay ; and the same is to be said of the greater part of the November 
storms. May and the first half of June and October with the first week of November 
are the only periods in which cyclones can be said to be prevalent in the north of the 
Bay, though they occur occasionally in the intervening months, that is, during the south- 
west monsoon. It will be sufficient therefore for my present purpose to consider the 
