EDITORIAL NOTES. IX 



regarded as including all information at present existing which is necessary 

 for the discussion of the broad questions raised in this Report. 



The Report itself is divided into two parts, the first dealing with 

 diurnal, and the second with monthly, annual, and recurring phenomena. 

 The former part is the first attempt yet made to deal with the diurnal 

 phenomena of meteorology over the ocean, --the pressure, temperature, 

 humidity, and movements of the atmosphere, together with such phenomena 

 as squalls, precipitation, thunder-storms and lightning. The results are 

 equally novel and important, and when combined with analogous results 

 obtained from land observations, enable us to take an intelligent and com- 

 prehensive grasp of these phenomena in their relations to the terraqueous 

 globe taken as one whole. In several cases, notably the diurnal phenomena 

 of atmospheric pressure, the results of observation will necessitate the revision 

 of all theories of the diurnal fluctuations of pressure that have assumed a 

 diurnal change of the temperature of the surface on which the atmosphere 

 rests as a necessary cause of these fluctuations. 



The second part of the Report attempts to give a comparative view of 

 the climatologies of the globe to a degree of completeness not previously 

 attempted. No effort has been spared to secure that the three outstanding 

 elements of climate, pressure, temperature and winds, be represented by 

 means for the same period of time, viz. the fifteen years ending with 1884. 

 This end has been virtually secured for nearly all the land surfaces of the 

 globe inhabited by civilized man, and this more particularly holds good in 

 extra-tropical regions, where averages for the same period of time become 

 more indispensable in discussing comparative climatologies. 



The Report extends to 342 pages of letterpress, and is illustrated by 2 

 plates of diagrams and 52 newly constructed maps, showing the monthly and 

 annual distribution of temperature and pressure of the atmosphere and 

 winds over the globe. Of these 52 maps, 2G shew the mean monthly 

 and annual temperature on hypsobathymetric maps, first on Gall's pro- 

 jection, and second on north circumpolar maps on equal surface projection ; 

 and 26 shew, for each month and for the year, the mean pressure of the 

 atmosphere and the winds. The circumpolar maps shew the distribution 

 of pressure and temperature in a manner more complete than is possible on 

 Gall's projection, and the data thus presented is in the most serviceable form 



(PHYS. CHEM. CHALL. EXP. PART V. 1889.) * 



