46 Journal of the Asiatic Society of Bengal. | February, 1908. 
The measurements of the time elapsed, and of the altitude 
and azimuth circles have latterly been taken and recorded by 
Babus Rakhaldas Chakravarty, Demonstrator. and Babus Rajani- 
kanta De‘and Janaki Nath Lahiri, Student-assistants in the Astro- 
nomical Observatory of the Presidency College. I have also 
received much ready assistance from Mr. 8. Woodhouse of the 
Mathematical Instrument Department. 
From the above it will be seen that a good deal of tronble is 
involved insuch observations, and that they cannot be made with 
any pretence to accuracy without fairly extensive preparations, 
and what is most difficult of all to obtain in this part of the world, 
skilled pence, 
not my intention to give in this paper the bes, or even 
a aaaideable part of the results I have obtained. I hope to have 
them worked out at leisure, and published elsewhere 5 ‘i have 
time and opportunity to look up the work done by others in this 
direction. Here I have little chance of keeping up with the times ; 
all I can hope for is to keep up with, and perhaps get ahead of, 
meteorological work in vr e! and its neighbourhood, no very 
ofty ambition as I understa 
One definite problem ohh T have had in view for some time 
is the calm region, a short way up during the cold season. One has 
occasional hints of its existence. For example, when the captive 
balloon at Olympia, two years ago, was cast loose for a voyage in 
space, it moved eastward and rose slowly until it reached this 
calm region. There it remained as if anchored for a long time. 
T accidentally saw it in that position and thought it must be fix 
by some mechanical means, it was so motionless. 1 subsequently 
saw in the newspapers that it was becalmed. 
n any ordinary cold weather day, when there is not very 
much wind, there is no difficulty in obtaining information of the 
height of the calm region and of the thickness of that layer of 
se air. One of the first series of observations I obtained at the 
s works was of a kind characteristic of the first half of the cold 
len and I will give figures and diagrams showing what the 
air currents were that sis the 19th December 1907, The 
former are given in the table immediately following, and the 
diagrams in Plate [. 
Imay explain that in the lower curve will be found the 
horizontal position of the balloon, the scale being 2,000 feet to the 
inch, with east and south in the usual topographical directions. 
The position of the balloon in the curve at the various times of 
observation, that is, at intervals of two minutes. is shown by the 
numbers at the side of = curve, these being the numbers of the 
‘ieee in the ta 
upper curve in the diagram gives the height of the 
‘elhakiy: the corresponding numbers of the observations Thserwk, 
sede along the base line, and the scale being 2,000 feet to the 
The observations Nos. 4,5, 6,7 ave of most importance in 
connection with the subject of this paper. From the observations 
os Saf TS snap oy 

