Berson,*  for  example,  dealing  with  data  obtained  from
manned  balloons  towards  the  close  of  the  last  century,  drew
attention  to  the  marked  constancy  of  the  lapse  rate,  about
5°  Centigrade  per  kilometre  (9C'  Fahrenheit  per  3,300  feet,
approximately),  up  to  a  height  of  4  kilometres  (roughly
13,000  feet),  and  to  the  sudden  and  considerable  increase  in
its  value  in  the  next  and  succeeding  layers.  He  attributed  the
change  to  the  fact  that  the  level  of  4  kilometres  marks  roughly
the  upper  limit  of  the  lower  clouds,  and  that  near  this  height
inversions  of  temperature  are  more  frequent  than  at  neighbouring
heights,  inasmuch  as  temperature  inversions  are  characteristic
of  the  top  of  such  cloud  layers.
Values  deduced  by  E.  G  old  from  later  manned  balloon  ascents
on  the  Continent  (1901-1907)  do  not  show  the  peculiarity  com-
mented upon  by  Berson  quite  so  clearly,  but,  nevertheless,
it  is  still  distinctly  noticeable.  Gold's  valuesf  are  given  in
Table  XII.
*  "  Wissenschaftliche  Luftfehrten,"  Braunschweig,  1899,  3  vols.
f  Geophysical  Memoirs,  No.  5.     "  The  International  Kite  and  Balloon
Ascents,"  E.  Gold,  M.A.     Meteorological  Office,  London,  1913.
102


TABLE  XII.
Upward  Temperature  Gradient.
Height:—

|

Kilometres

0-1

1-2

2-3    i    3-4

4-5

5-6

6-7

7-8

Feet   (in   hun-

0-33

33-66

66-98

98-131

131-

164-  |  197-

230-

dreds).
164

197    i    230

262

i

Gradient  :  —

Degrees  Abso-

4-3

5-1

5-1

5-8

6-2

6-9

7-5

6-2

lute.
Degrees   Fahr.
