,,vol4 ,,iii1 ,,pp4 #da-eb1 ,,may #a1   
#ahia    ,,the ,,national ,,geographic  
,,magazine          ,,geography ,,of    
,,the ,,air    ,,annual ,,report ,,by   
,,vice-,,president    ,a4 ,w4 ,,greely  
,,washington    ,,published ,,by ,,the  
,,national ,,geographic ,,society       
,price #be ,cents4      #da      ,,vol4 
,,iii1 ,,pp4 #da-eb1 ,,may #a1 #ahia    
,,the ,,national ,,geographic ,,magazine
          ,,geography ,,of ,,the ,,air4 
,,annual ,,report ,,by                  
,,vice-,,president    ,a4 ,w4 ,,greely4 
7,presented to the ,society ,january    
#bc1 #ahia47      ,in fulfilling the    
duties growing out of his official      
position in  connection with this       
,society1 your ,vice-,president of the  
,geography of  the ,air has been so     
closely occupied with executive and     
other official  duties devolving upon   
him as to preclude his giving that      
amount of  time and labor to this annual
 report that the subject merits4        
,indeed1  no report would be submitted  

this year had it not seemed better to   
insure a continuity of these annual     
addresses1 even if one of them  might   
not be up to the high standard which    
should be maintained for  them4    ,it  
must have impressed every general reader
 of scientific journals  that the past  
year has been marked by the publication 
of an unusual  number of controversial  
articles relating entirely or in part to
  meteorology4 ,some of the discussions 
of this subject appear to be in  the    
nature of speculation1 which1 by good   
authority1 is defined to be  chiefly the
 work of the imagination1 and has little
 to do with  realities4 ,the status of  
the meteorological discussion which has 
been  going on for some time seems to be
 this3 ,a number of men1 applying       
themselves to investigation in separate 
branches or stages of the same  science1
 are attempting to reconcile their      
views1 which1 based as they  are upon   
entirely different processes of         
investigation1 are not  entirely        

accordant4 ,some1 at least1 of these    
writers are still  apparently groping in
 the preliminary1 the natural history   
stage of  the #db science of            
meteorology1 while one alone stands as  
the  exponent of the natural philosophy 
of meteorology4    ,to me it seems that 
it could not have failed to impress any 
interested  reader who has followed the 
late publications on the convectional   
theory that1 in order to clear the      
ground for definite meteorological      
discussion1 it is necessary to determine
 the exact meaning of the  various      
technical terms employed by the various 
writers4 ,whether from  looseness of    
verbiage originally or from the not     
infrequent habit of  disputants when    
worsted to change their ground by       
claiming to be  misunderstood1 we find  
that some writers are unwilling either  
to stand  by their first criticisms or  
to openly abandon them2 they prefer to  
explain away their defective statements 
and gradually shift around to  positions

 almost diametrically opposed to those  
originally assumed4    ,the generally   
accepted theory as to cyclones          
attributes their  initiatory formation  
to an unequal distribution of           
temperature with  resulting mean        
diminution of pressure1 and the movement
 of the air  from places of high to     
places of low pressure1 the lower air   
ascending  with a gyratory motion1 while
 air particles moving from opposite     
directions form couples which produce   
rotation4 ,when energetic motions  raise
 the ascending air to such a height that
 the temperature1 cooled  dynamically in
 ascending1 goes below the dew-point1   
then the great  store of latent heat    
thereby set free becomes1 it is assumed1
 the main  source of energy in          
maintaining the upward convectional     
movement4 ,the  subsidiary causes are   
attributed to the diminution of pressure
 on the  collapse of the vapor1 and also
 to the direct absorption of the sun's  
heat at the upper cloud surface4    ,in 

anticyclones a slow gyratory descending 
motion of the air is  assumed4 ,ferrel  
considers the cyclone and anticyclone   
one system1 and  believes that air      
flowing into the cyclone from a high at 
the ground  passes out into the higher  
atmospheric strata4    ,dr4 ,hann has   
put forth the hypothesis that the       
genesis of cyclones and  anticyclones   
may be sought in the general atmospheric
 circulation  through a difference of   
temperature of the air from the equator 
to the  poles4 ,he speaks of a          
congestion in the upper or anti-trade   
winds1  where the air heaps up to a     
great height1 this being the cause of   
the  anticyclones2 and he maintains that
 the low temperature of the high  is due
 to ground radiation1 and that no part  
of the high pressure is  the result of  
low temperature4    #dc ,to this        
hypothesis of ,dr4 ,hann1 ascribing the 
genesis of storms  to the general       
circulation of the atmosphere1 no       
application of the  laws of dynamics has

 yet been made with a view of developing
 it into  an acceptable theory4 ,if it  
should be established it does not follow
  that it will in any way affect the    
truth of the commonly accepted          
convectional system1 which1 founded as  
it is on the well-known laws  of        
thermo-dynamics1 is not likely to be    
successfully assailed4 ,there  may be an
 improved nomenclature for the laws of  
statics and dynamics  that will express 
to the mind more clearly the relation of
 cause and  effect2 but until the       
advance of scientific research modifies 
the  present formulation of these laws  
the convectional theory will be         
generally accepted as giving the true   
interpretation of all the  phenomena to 
which it could be applied4    ,professor
 ,russell1 in commenting on this        
subject1 expresses the  opinion that the
 low temperature is due to the          
convective interchange  of air at a low 
temperature in the upper strata with air
 of a high  temperature in lower strata1

 such convective interchange tending to 
make the whole body of air of a         
temperature coinciding throughout with  
the adiabatic rate of upward diminution1
 with the consequent result of          
rendering the air at the surface of the 
earth cooler than previously  and the   
upper air warmer4 ,when the upward      
diminution of temperature is  less than 
the adiabatic rate1 in the forced       
circulation of air  crossing a mountain 
ridge1 there occurs the dynamic heating 
which is  observed in the case of the   
foehn winds4 ,the low temperature near  
the  earth he does not believe could    
ever be entirely produced by nocturnal  
radiation from the ground4 ,the high    
pressure1 in his opinion1 is  largely   
the result of greater density due to low
 temperature1 as is  very clearly       
indicated by the fact that the          
temperature is almost  inversely        
proportional to the pressure1 and that  
the places of lower  temperature        
substantially coincide with the places  

of greatest  pressure4    ,in advancing 
hypotheses and inviting discussion the  
real object is1 or  at least should be1 
to discover the essential cause or      
causes which  determine the initial     
formation and subsequent maintenance and
  progress of the cyclone4 ,some real   
progress in charting lines of equal     
density seems to have been made by ,m4  
,nils ,ekholm following ,professor      
,abbe's system of isostaths1 one using  
the term density1 the other  buoyancy4  
,professor ,abbe also introduces the    
factor of the orographic  gradient1 but 
the #dd latter is simply the measure of 
a resistance4  ,the objection to this   
form of determination is this1 that it  
is a  measure of mass only4 ,the density
 of two masses of air is determined  to 
be the same2 but as the density may     
result from two entirely  different     
causes1 their physical relations cannot 
be fully expressed  in units of gravity4
 ,the methods of ,professor ,abbe and of
 ,m4 ,nils  ,ekholm undoubtedly give    

good results1 partly from the           
coincidence that  humidity usually      
varies directly as the temperature4     
,the method proposed by ,captain ,james 
,allen in #ahhh1 which is briefly       
described in appendix #bd to the annual 
report of the ,chief ,signal  ,officer  
for #ahij1 appears to afford the means  
of more clearly  expressing the         
relations that exist between the mass of
 the atmosphere  and the forces         
available for the generation and        
movement of storms4  ,its tentative     
application at the ,signal ,office has  
anticipated and  explained storm        
movements not indicated or accounted for
 by the usual  methods4    ,as pertinent
 to this matter1 there is instanced a   
study of the  progress of thunder-storms
 made by ,berg1 who observes that the   
line of  storm front in every case      
investigated made a decidedly           
conspicuous  bend into the densest part 
of the lines representing the absolute  
humidity4           99       99       99

       99       99    ,scientific       
conditions have so changed that in these
 later years it  becomes more and more  
difficult for investigators to publish  
any work  which may be characterized as 
magnum opus4 ,under this head1 however1 
must be classed ,buchan's important     
memoir on the distribution of           
atmospheric pressure1 temperature1 and  
wind direction over the whole  world2 a 
large quarto volume1 which contains much
 new material4 ,it has  been            
incorporated with the results of        
observations during the  ,challenger    
expedition1 in which series this work   
appears4 ,the isobars  and isotherms for
 each month in the year for the whole   
earth are  charted on ,mercator's       
projection1 and for the northern        
hemisphere on a  chart constructed on a 
polar projection4 ,in connection with an
  abstruse subject1 to which ,buchan has
 paid so much attention1 the  diurnal   
variation of pressure1 he opines from   
the ,challenger  observations that the  

oscillations are due to the heat taken  
from the  solar rays directly in passing
 through the air and instantaneously    
communicated through the whole mass from
 top to bottom by heating and           
evaporation of water on innumerable dust
 particles4 ,the afternoon  minimum1 he 
thinks1 is caused by upward currents    
removing a portion of  the lower air4   
,marked #de differences exist between   
the continental  and insular types1     
since on islands the morning minimum is 
unusually  large and the afternoon      
minimum so small as to disappear1 while 
in  continental types the reverse       
conditions obtain4           99       99
       99       99       99    ,werner  
,von ,siemens1 in answering ,sprung's   
criticism on his general air  currents1 
after repelling certain statements of   
,sprung1 describes his  own theories1   
which are worthy of restating3    #a4   
,all winds are caused by the            
disturbances of indifferent             
equilibrium1 and the motion of the air  

is to restore equilibrium4    #b4 ,these
 disturbances are caused through        
overheating of the layers of  air near  
the surface of the earth by insolation1 
through unsymmetrical  cooling of the   
higher layers by radiation1 and through 
the heaping up  of air masses caused by 
obstructions4    #c4 ,the disturbances  
are adjusted by ascending currents1     
wherein the  particular species of      
acceleration occurs in which the        
increase of  velocity is proportioned to
 the diminution of pressure4    #d4 ,the
 upward currents correspond to equally  
great descending currents  in which     
there is a decrease of velocity         
corresponding to the  acceleration in   
the upward velocity4    #e4 ,if the     
region of overheating of the air is     
limited locally1 a local  upward current
 reaching to the highest layers of air  
arises1 and  whirlwinds appear with     
interior spirally ascending currents and
  outside similar spiral descending     
currents4 ,the result of this is        

dispersion of the superfluous heat of   
the lower air by which the  adiabatic   
equilibrium is disturbed throughout the 
whole column of air  taking part in the 
whirling motion4    #f4 ,in case the    
region of disturbance of the indifferent
 7or adiabatic7  equilibrium is very    
extensive1 as1 for example1 the whole of
 the  tropical zone1 the temperature    
adjustment can no longer be             
accomplished by locally ascending       
whirls1 and a whirling current must     
then arise involving the whole          
atmosphere4 ,the same conditions apply  
to these as to the local whirls of      
accelerated upward motion and  retarded 
descent in such a manner that the       
velocity at different  altitudes arising
 from heat converted to work is         
approximately  proportional to the      
prevailing pressure at the place4    #g4
 ,in consequence of the meridional      
motion produced and maintained by       
conversion of heat into work1 the whole 
atmosphere in every latitude  must      

rotate with approximately the same      
absolute velocity4 ,thus the  meridional
 currents produced by overheating       
combine with the currents  embracing the
 whole #df wind system of the earth1    
with the result of  disseminating the   
excess of temperature and humidity of   
the torrid  zone over the temperate and 
arctic zones1 thereby producing the     
prevailing winds4    #h4 ,this is       
accomplished by the production of       
alternating local  depressions and      
elevations of barometric pressure by the
 disturbance  of indifferent equilibrium
 in the upper layers of the air4    #i4 
,highs and lows are a consequence of the
 temperatures and  velocities of the    
upper currents4    ,whence it follows   
that the most important problem of      
meteorology is  the investigation of the
 causes and consequences of the         
disturbance of  indifferent equilibrium 
of the atmosphere1 and the weightiest   
problem  in weather prediction is the   
investigation of the geographical origin

  or extraction of air currents pursuing
 their course above us toward  the pole4
           99       99       99       99
       99    ,in ,pomortsew's treatise  
on synoptic meteorology1 published in   
,russia1  there are full chapters on    
prediction of weather1 whether from     
synoptic charts1 from observations at a 
single place1 or from  prognostics of   
great length based on researches on the 
succession of  warm and cold months4 ,it
 also contains ,pomortsew's             
investigations on  the types of pressure
 distribution in eastern ,europe1 as    
well as the  average path of cyclones4  
99       99       99       99       99  
,the favorable opportunities afforded by
 the ,eiffel tower have been  utilized  
by ,french meteorologists4 ,m4 ,angot   
states that during the  anti-cyclone of 
,november1 #ahhi1 the temperature on the
 tower was  several degrees higher than 
below4 ,the change of weather set in    
earlier1 with a strong and warm wind1 on
 the tower1 while the air at  the ground

 was cold and calm4 ,wind observations  
on the tower show a  ratio of #c4a at   
that height 7#cjc meters7 to the        
velocity at a height  of #ba meters1 as 
determined from #aja days' observations1
 which1  remarkable at such a small     
height1 discloses the peculiarity of    
high  mountain stations4           99   
99       99       99       99           
,partsch1 writing on evidence of        
climatic changes within historical      
times in the ,mediterranean region1     
remarks that too much attention has     
been given to changes in crops1 the     
introduction of plants1 and the  limits 
of domestic animals4 ,he states that    
existing information as to  the harvest 
time of ancient days indicates an       
unchanged climate1 while  the           
land-locked lakes in ,tunis1 which      
afford the best evidence on  rainfall   
variation1 show absolutely no climatic  
change4           99       99       99  
99       99    #dg ,van ,bebber1 in     
writing on weather types1 claims that a 

line drawn  from the center of a cyclone
 perpendicularly in the direction of the
  heaviest gradients will in general be 
perpendicular to the subsequent  path of
 the low1 and that these lows leave high
 temperature on the  right hand4        
99       99       99       99       99  
,hill1 in describing hail-stones and    
tornadoes in ,india1 explains them  on  
the principle of the great diminution of
 temperature upwards in the  air1 but a 
critic1 in combating this theory1       
objects to the high and  low stations   
selected to show temperatures4          
99       99       99       99       99  
,the so-called weather plant of the     
tropics has passed through the  process 
of investigation with the usual result4 
,it appears surprising  that in these   
days it should be believed that any     
plant or animal can  foretell weather   
#dh hours in advance1 particularly after
 considering  the vast amount of proof  
as to the enormous rapidity with which  
weather-changes progress from day to    

day4           99       99       99     
99       99    ,hugo ,meyer1 in treating
 the precipitation of central ,germany  
for the  ten years ending in #ahhe1     
pertinently remarks that the same       
significance does not attach to the same
 rainfall for all places and  different 
times of the year1 for this average     
value is not the amount  most likely to 
fall in any particular interval of time1
 since there is  a limit to the extent  
of the negative deviations on one       
side--that is1  #j or no rainfall1 while
 on the positive side there is no limit4
 ,the  most probable depth of rainfall1 
therefore1 is less than the mean  value1
 the preponderance of negative over     
positive deviations being  about #aj per
 cent4 and sometimes as great as #bj per
 cent4           99       99       99   
99       99    ,professor ,w4 ,m4 ,davis
 wrote an interesting review of         
,professor  ,ferrel's popular treatise  
on the winds1 published a year ago4     
,commenting on the review1 the editor of

 ,meteorologische ,zeltschrift1         
,vienna1 remarks on a very important    
omission in the treatise1 namely1  the  
absence of all reference to the diurnal 
variation of the wind and  the many     
interesting relations it bears to other 
phenomena1 a notable  omission in a     
treatise specially devoted to winds4    
,the treatment of  the monsoon wind and 
its relation to the general circulation 
is highly  commended by the editor1 and 
indicated as being all new4           99
       99       99       99       99    
,your ,vice-,president has elsewhere    
expressed his opinion that monsoon      
winds1 applying the term by liberal     
construction to signify winds  which    
recur with returning seasons1 cannot    
with #dh any degree of  correctness be  
asserted to prevail in the ,united      
,states4 ,it is true  that the          
prevailing surface winds of the greater 
part of the ,united  ,states come from  
the western quadrants--that is1 between 
southwest and  northwest--and so are in 

substantial harmony with the general    
atmospheric circulation as shown by the 
upper-wind currents of ,mount           
,washington 7from the northwest7 and    
,pike's peak 7from the southwest74      
,but1 apart from the easterly and       
northeasterly trades on the ,florida    
coast1 it appears from the records that 
in no case for any  considerable section
 of the country do #ej per cent4 of the 
winds blow1  for any consecutive number 
of months1 either from any single point 
or  from two neighboring points of the  
compass4 ,occasionally1 however1 the    
local configuration of the country is   
such that winds are drawn up or  down   
valleys1 and1 being diverted from their 
free and proper  direction1 the wind in 
such cases follows the trend of the     
valley or  depression4           99     
99       99       99       99    ,in    
general your ,vice-,president would feel
 inclined to refer only  casually to the
 work proceeding from the ,bureau over  
which he has the  honor to preside1 but 

this year has been marked by special    
researches  and investigations of       
general interest4 ,as the work of       
investigation  has been entrusted to the
 professors of the ,signal ,service1 due
 credit  should not be refused them from
 their own official chief4    ,special  
reference should be made to the work of 
,professor ,charles ,f4  ,marvin1 whose 
successful experiments on wind pressures
 and velocities  have attracted the     
attention of experts both in ,europe and
 in this  country4 ,unfortunately there 
was available only a small sum 7about   
one  hundred dollars7 for the expense of
 experiments1 but with this petty  sum1 
supplemented by his ingenuity1          
,professor ,marvin has very             
satisfactorily determined the           
cofficients of the various forms of the 
,robinson anemometer1 with which        
instrument the velocity of the wind is  
very generally determined4 ,following   
these investigations1 the ,royal        
,meteorological ,society of ,england    

reopened the question1 which1 after  a  
costly set of experiments with results  
widely differing from those  of         
,professor ,marvin1 had been considered 
closed4    ,the general results of these
 researches1 which are believed to be   
sufficiently definite for general       
questions1 are not only prized by  the  
scientist1 but they are of value to the 
engineer and the builder4  ,indeed1 to  
all interested in costly structures or  
extended works  liable to harm from wind
 pressures1 the factor of safety is #di 
a  matter of no small pecuniary         
importance4 ,these experiments show     
that1  as was formerly believed to be   
the case1 the wind pressure varies as   
the square of the velocity of the wind1 
expressed in miles per hour2  but a most
 important fact has developed1 namely1  
that the pressure in  pounds per square 
foot is equal to the miles of hourly    
velocity  multiplied by #j4jjd instead  
of #j4jje1 as was formerly assumed4     
,professor ,marvin was not content with 

one system of experiments1 but  he      
further attacked the problem in a direct
 manner by a method which  checked and  
verified his experiments with the       
whirling machine4 ,on the  summit of    
,mount ,washington1 at an elevation of  
#f1cjj feet1 he obtained  simultaneously
 and under the same conditions1 by      
automatic and  electrical apparatus1    
continuous registration of the pressure 
of the  wind in pounds per square foot  
and of the velocity in miles per hour4  
,the results thus verified can be       
considered as conclusive from a  general
 standpoint4 ,the corrections for the   
,robinson anemometer thus  determined   
from these experiments are comparatively
 unimportant at low  velocities1 say    
from #aj to #ae miles per hour1 being   
only a fraction of  a mile per hour4    
,the uncorrected velocities1 however1   
are in all cases  too large1 and by     
greater and greater amounts the higher  
the velocity4  ,at #fj miles per hour   
the observed velocities are about #ab   

miles per  hour too high1 and for an    
indicated velocity of #ij miles the     
experiments show that the actual        
velocity is but a fraction over #fi     
miles per hour4    ,the anemometer      
formula found to satisfy most closely   
the entire range  of experiments has the
 following form for velocities in miles 
per  hour3      ,log4 ,v  #j4eji        
#j4ijab log4 v4    ,this difference     
indicated by the formula may seem small 
and  insignificant1 as it is in the case
 of light winds1 but at very high       
velocities the differences are very     
great4 ,for instance1 an actual         
velocity of #fj miles per hour may occur
 at some time in almost any  locality of
 the ,united ,states for a few minutes1 
and even greater  velocities are        
occasionally reported1 apart from severe
 tornadoes4  ,under the old cofficients 
for the ,robinson anemometer an actual  
velocity of #fj miles per hour would    
have been reported as #gg miles per     
hour1 which under the old factor of     

#j4jje would mean a pressure of  #bi4f  
pounds per square foot2 but when        
considered with reference to the  true  
velocity of #fj miles1 under #ej the new
 factor of #j4jjd1 the  pressure would  
only be #ad4d pounds per square foot--a 
reduction of  over #ej per cent4 from   
the pressure-values formerly accepted4  
,professor ,marvin has undertaken to    
verify1 and also to extend to even      
lower temperatures1 the observations of 
,regnault as to the pressure of  aqueous
 vapor at low temperatures1 especial    
attention being given to  temperature   
conditions from #j centigrade to -#ej   
centigrade4 ,these  observations        
disclose1 below #j centigrade1 small but
 constant  differences from the values  
assigned by ,regnault4    ,in all this  
work ,professor ,marvin has shown such  
ingenuity of  resource1 such skill in   
adapting means to the end1 and such     
deftness  in improvising and            
manufacturing the requisite instruments 
as have  elicited commendation from all 

who have seen his work and followed his 
methods4 ,your ,vice-,president alludes 
to this not only to give that  credit   
rightfully due to ,professor ,marvin1   
but to illustrate this as a  type of the
 highly important work which is being   
done in all branches  of science here in
 ,washington by young men sometimes illy
 equipped as  to means1 and still more  
illy paid4 ,men engaged in work of      
original  investigation should receive  
higher pay than clerks in charge of     
routine duties2 but unfortunately the   
majority of them do not4           99   
99       99       99       99    ,the   
work of ,professor ,hazen in charting   
tornadoes and in determining  their     
relative frequency and severity is      
directly in the line of the  ,geography 
of the ,air4    ,great attention had    
previously been given to this subject by
  ,lieutenant ,john ,p4 ,finley1 who1   
with indefatigable industry1 had        
accumulated an enormous mass of data    
relative to these violent  outbursts of 

nature's forces4 ,the figures and       
deductions previously  put forth under  
the authority of the ,signal ,service   
having been  questioned1 the ,chief     
,signal ,officer felt obliged1 in view  
of the  growing practical importance of 
the question1 as indicated by the  great
 sums annually paid out in the ,ohio    
valley and in the  trans-,mississippi   
region for protection against tornadoes1
 to repen  the subject4 ,instructions of
 the most conservative character were   
given to ,professor ,hazen to determine 
carefully the prevalence and  number of 
tornadoes in the ,united ,states1 the   
areas devastated by  them1 and the      
number of lives lost annually4 ,this    
work was carefully  scrutinized during  
its progress to see that it should be   
devoid of  theory and rest on the solid 
basis of fact4 ,the results are most    
assuring to every #ea one1 and must     
serve to allay the unreasonable  fears  
of the inhabitants of the so-called     
tornado districts4 ,it  appears that    

there is no part of the ,united ,states 
in which annually  more than one square 
mile of devastation or severe           
destruction can be  expected for each   
#ahe1jjj square miles1 although cases of
 limited  destruction may occur annually
 for about every #e1jjj square miles of 
area4 ,in no state may destructive      
tornadoes be expected1 on an  average1  
more than once in two years2 and the    
area over which total  destruction can  
be expected is1 as shown by the         
foregoing figures1  exceedingly small1  
even in localities most liable to these 
violent  storms4 ,the annual death      
casualties from tornadoes have averaged1
 in  the last #ah years1 #ajb annually2 
but it is believed that the death  rate 
from lightning is greater than that from
 tornadoes1 since during  ,march to     
,august1 #ahij1 the names of #aaj are on
 record who have lost  their lives by   
lightning1 although the data are        
incomplete1 especially  as regards the  
southern states4 ,these statistics      

cannot be passed by  lightly1 however1  
and it is doubtful if in the main they  
are much in  error4 ,by them it appears 
from five years' record that the average
  annual death rate by lightning in the 
,united ,states is #c4h per million  of 
inhabitants1 or #j4b above the average4 
,in ,sweden1 for sixty years1  the      
average has been #c4j2 in ,france1 for  
forty-nine years1 #c4a2 in  ,baden1 for 
seventeen years1 #c4h2 and in ,prussia1 
for fifteen years1  #d4d per million4   
,other figures1 given by a              
life-insurance agent in ,st4 ,louis1    
which the  author claims to have        
compiled with great care1 place the     
average  annual rate of death from      
lightning in the ,united ,states at     
#bjf1 being  more than double the deaths
 from tornadoes4 ,it must be understood 
that  these figures are not vouched for1
 and must be very cautiously  received1 
as originating with companies interested
 pecuniarily in the  statistics4    ,on 
the whole1 therefore1 it may be safely  

assumed that tornadoes are  not so      
destructive to life as thunder-storms4  
99       99       99       99       99  
,professor ,thomas ,russell has         
formulated a method for prediction of   
cold waves4 ,they always occur after    
lows and before highs1 and  different   
cold waves vary in extent from three    
units to sixty4 ,a  unit of             
temperature-fall is taken as a fall of  
twenty degrees over  an area of #ej1jjj 
square miles4    ,the temperature-fall  
curves in the ,united ,states are       
approximately  elliptical in shape4     
,perfect ellipses represent actual      
temperature  falls with an error not    
exceeding six degrees in #eb most cases4
  ,these fall lines are intersections of
 planes with a cone which  graphically  
represents the totality of              
temperature-fall1 the contents  of the  
cone being equal to the area of its base
 multiplied by its  altitude1 which is  
the greatest fall in temperature at the 
center of  the cold wave4    ,a formula 

has been devised1 based on #abg special 
cases1 representing  the amount of fall 
in terms of the amount of barometric    
depression in  a low1 and the amount of 
excess if a high1 and the density of the
  isothermal lines in the region4       
,from proper consideration of the type  
of low area1 shape of isobars1  and     
position of the long axis1 definite     
conclusions can be drawn as to  the     
subsequent shape of the elliptical      
twenty-degree temperature-fall  area and
 its position4    ,a method has been    
devised1 also by ,professor ,russell1   
for determining  the maximum fall of    
temperature at the center of the cold   
wave4 ,the  maximum fall and extent of  
fall being known1 from suitably prepared
  tables1 the area of twenty-degree fall
 can be derived4 ,previously  prepared  
pieces of card-board are laid in the    
proper position on a map  of suitable   
scale1 and lines drawn around them4     
,between the line  representing the     
twenty-degree fall and the center1 the  

other falls of  thirty degrees1 forty   
degrees1 etc41 are sketched in4         
99       99       99       99       99  
,the foregoing sketch of the geography  
of the air may appear too  superficial  
and limited for the purposes of this    
,society1 but its  further elaboration  
was impracticable4 ,indeed1 the subject 
of  meteorology could hardly have been  
touched upon this year had it not  been 
for the courtesy of ,professor ,russell 
in placing at my disposal  notes upon   
translations from foreign publications1 
especially from the  ,german2 which     
publications ,i have been unable to     
examine save in a  casual way4    ,the  
address1 as it is1 is submitted only in 
the hope that it may  serve1 if no other
 purpose1 at least to indicate the great
 interest  which now obtains in the     
geography of the air1 and which         
manifests  itself in the production of  
meteorological pamphlets and            
publications  too numerous to permit any
 one charged with important executive   

duties  to examine them all1 even in a  
non-critical way4