602 
Tliis  was  writteri  in  1904.  Since  tlien,  tlying  has  beconie  safer, 
and  walking  less  safe  — but  stiil  tliere  remains  Iruth  enough  in 
tlie  coinparison,  and  it  is  to  these  investigations  on  the  firm  ground 
of  facts  that  yon  have  devoted  yonrself  since  the  leadership  of  the 
Meteorological  Office  in  England  was  entrnsted  to  you  in  j900. 
In  order  to  approach  the  aini,  the  walker  must  know  liis  ground, 
and  yon  recognised  trom  the  beginning,  thanks  certainly  also  to  your 
membership  of  tlie  Meteorological  Council,  what  obstrnctions  and 
pitfalls  were  lying  about.  You  canie  to  the  office  with  sornething  like 
20  years’  practice  as  a teacher  of  experiinental  physics,  and  so  one 
of  your  tirst  occupations  has  been  to  advocate  the  use  ofthemetric 
System  in  ineteorology.  For  scientiüc  aerological  research  this  system 
was  adopted  internationally  at  Vienna  in  1912:  if,  on  our  weather 
maps  and  in  our  inessages  the  battle  between  millimeter  and  millibar 
is  stiil  raging,  and  Fahrenheit  degrees  have  not  been  abandoned  for 
absolute  temperatures,  it  is  not  your  fault  — but  at  all  events,  tlie 
inches  have  been  got  rid  of. 
In  the  same  line  werê  your  elforts  in  favour  of  uniform  projection 
and  scale  of  meteorological  charts;  these  led  you  to  the  construction 
of  the  ,,octogonal  globe”,  giving  a nearly  eqiial  area  projection  of 
the  whole  surface  on  plane  polar  caps,  conical  temperate  and  cy- 
lindrical  tropical  beits,  capable  of  being  reproduced  by  printing  on 
a plane  sheet. 
A more  direct  attack  of  the  problem  what  the  motion  really  is 
was  iindertaken  in  your  various  researches  on  the  trajeetories  of  air, 
the  life  history  of  surface  air  currents,  published  in  cooperation  with 
your  assistant  Mr.  Lempfert.  Here  direct  evidence  is  given  of  air 
escaping  from  the  surface  or  siipplied  to  it  from  above  — and  the 
causes  were  shown  of  the  many  variations  in  intensity  or  duration 
of  rainfall  associated  with  slow  or  fast  travelling  storms,  V-shaped 
depressions  and  squall-lines. 
The  problem  of  the  great  circulation  and  its  connexion  with  the 
energy  of  cyclones  has  been  the  subject  of  many  of  your  investiga- 
tions. You  have  shown,  that  the  normal  condition  of  the  atmo- 
sphere  is  one  in  which  the  gradiënt  is  exactly  balanced  by  the  velocity, 
so  that  as  a firsl  approximation  isobars  become  identical  with  stream 
lines.  After  extending  Teisserenc  de  Bort’s  isobars  at  4 kilometers 
to  8 kilometers,  you  have  pointed  out  that  at  8 kilometers  the  density 
is  the  same  all  over  the  globe  in  all  seasons  of  the  year,  and  that 
the  isobars  at  8 kilometers  very  mach  resem ble  the  curves  repre- 
senting  the  weight  of  the  lower  8 kilometers,  but  with  a reversal 
of  sign  as  to  high  and  low.  This  shows  that  neither  the  knowledge 
