vi 
From the Preface 
When these sketches were first pre- 
pared it was thought that the sub- 
ject would develop so rapidly that 
any attempt to simulate a_ well- 
rounded and comprehensive treatise, 
even for beginners, would not be 
justified nor feasible. Needless to say 
the continued warm response and wide 
influence which the work has had has 
left the authors and editors with a 
sense of responsibility for which they 
had not bargained. The authors feel 
that most of the early principles of 
air mass analysis still bear a funda- 
mental value for synoptic practice, so 
that extensive revisions have not been 
necessary in this new edition, though 
references are made here and there to 
some of the points that have been 
particularly altered or questioned in 
light of more recent developments. 
From the practical point of view, 
the beginner in America now has 
much better opportunities to “pick up” 
experience through his own efforts 
than when this “Introduction” first 
appeared over three years ago, when 
no competently analyzed air-mass 
weather maps were available outside 
of a few institutions and special serv- 
ices and none to the public. At pres- 
ent, thanks to the remarkable changes 
in U.S. ‘Weather Bureau _ practice 
since 1934, such maps may be in- 
spected by anyone at a large number 
to the 4th Edition 
of airport and city offices of the 
Bureau, and many of their personnel 
can now produce or interpret analyses 
acceptably, while at the Central Office 
in Washington competent and funda- 
mental research is being carried on. 
(The problem of rapidly training a 
large organization in such a different 
technique is admittedly difficult). 
The present “Introduction”, how- 
ever, should not be regarded as one to 
the whole field of synoptic meteor- 
ology. For such a serious ambition 
one should study physical meteorology 
as well, and there are excellent gen- 
eral texts such as Humphreys’ “Phys- 
ics of the Air’, Brunt’s “Physical and 
Dynamical Meteorology’, Taylor’s 
“Aeronautical Meteorology”, “Byers’ 
“Synoptical and Aeronautical Mete- 
orology”’, [and now (1940) also Pet- 
terssen’s “Weather Analysis and 
Forecasting”, Sutcliffe’s “Meteorology 
for Aviators’, and “The Admiralty 
Weather Manual’’,] to lighten the 
road. But to that large audience 
which desires only a brief, authorita- 
tive, and inexpensive “first reader” 
in this fascinating concrete way of 
looking at the weather, this booklet 
is offered again in the hope that 
it will continue the instrument for 
wide dissemination of modern me- 
teorological principles which it has 
been.—Robert G. Stone, Oct. 1938. 
