416 TRANSACTIONS OF SECTION A. 
giving a vertical velocity of ascent of about 3m.p.s. The instiuhents were 
the light meteorographs designed by W. H. Dines, F.R.S., and weighed, 
with the protecting case, about 60 gm. Table I. gives the average tempera- 
ture at different heights deduced from the nineteen records obtained. 
TaBLe I.—Average Temperature at successive Kilometre Levels during the period 
June 2,7 p.M., to June 3,7 P.m., 1909. 
Height. Temperature Height. Temperature 
Kilometres EG: Kilometres are. 
0 11 10 —AT5 
1 3 11 —49 
2 0 12 —47 
3 —4 13 —46 
4 —85 14 —46°5 
5 ~—15 15 —4T5 
6 —22 16 —48°5 
7 —28°5 17 —48 
8 —35 18 —48 
9 —42 
Almost all the balloons fell within a range of 100 km. They were fairly 
uniformly distributed along a line between the points 80 km. N. 56° E. and 
30 km. N., the early ones falling at the former, the later ones at the latter 
point. 
It is seen that the temperature fell rapidly to a height of about 10 km., 
the average gradient being 5°7° C. per kilometre. Above this height there 
was a sharp rise of temperature, but above 12 km. the changes were small. 
TaBLe Il.—Temperature at successive 2-Kilometre Intervals during the period 
June 2,7 P.M., to June 3, 7 P.M., 1909. 
Height in Kilometres 
Time r 
0 2 4 6 8 10 12 14 16 18 
7 rar : 191 | 74 |2o4,|=84. |—e& |—405|—4e-5 | 48 |Sedrel one 
” e ame — =e a = Fa ra —~ Tz oa, a7 
Bre: 109 | —o'5|-9:5 |~93 |-36 |~505|—46 |-47-5|—515| —= 
” 8 . = ren =a =e oe — <= = = = 
Wee oe he ee Aa aah |. gag Lae |oge5 | = 
12 midnight .| — == —= — — = a z= ae as 
Jam. .) 82 | ~4 12:5|=26 |-41 |~s52-5|/-49 |-51 |-525|—525 
Boy 73 | ~2 |-96 |~205|-34 |—46-5|—48-5|—46-6|~48-5|—60 
ae 75 | —1,.|=65. Heats | Se. | 46 |—45 Jl odg eee ae 
6 ian 78 | ~35|—19-5|—24-5|—36-5|—48-5|/-46 |-46-5/—49 |—48-5 
Be ee | | AS a Sa oe oo ee a 
Le 11 | 415/-6 |—20 |~31-5|—44-5|—495|—49 |~44-5|—435 
10 Z 18. | 405/285 |-or |—a95|2455|47 |L4e5 See o) 
12 noon 4 | 415|-55 |-175|-30 |-46 |=45 |49-6| een ae 
PM. « _ —_ — — a —_ — — — —a 
Tigh iets 146 | 41 |~95 |+196|~33 -|—445 |—45-5.|—43-5|4a5 | 45-5 
Bo cee, 147 | 405|-8 |—20 |-34 |~485|—505|—455|—49 |L47-5 
: A i 125 eco joe dies |—a4. |=a7-5l 48 | 50m | eee 
6°. |. P86 OSs lar lBa7" }59-6)| 250 "| 2465 eee 
Ties 6) 1264 LOslSa0h Sos Near 55 | 
