496 SCIENTIFIC RECORD FOR 1883. 



general character of the weather in the latter zone. Therefore, by the 

 observations in the temperate zone alone we can never completely trace 

 its weather back to its fundamental causes." 



'In closing our summary of Hann's important work we may be par- 

 doned for referring to the great stride made during the past twenty 

 years in our knowledge of meteorology, and to the Americans, Henry, 

 Espy, and Ferrel, who have correctly penetrated to the ultimate causes 

 and laws of the principal phenomena. Their views have a most pro- 

 found influence in the daily work of the Weather Bureau of the Army 

 Signal Office, and are amply illustrated in its daily maps and monthly 

 reviews, and are now become the foundation of such works as the 

 present by Hann. Especially has the present writer never ceased to 

 urge the necessity of studying the atmosphere of the whole globe in 

 one comprehensive chart. To this end the Bulletin of International 

 Simultaneous Observations was undertaken, and it already offers data 

 for solving the difficult climatological problems that Hann has so 

 clearly set forth. Great mathematical problems delay the progress of 

 the work ; as with Faraday in electricity, and many other physicists, so 

 here, doubtless, the observational and inductive methods must always 

 prepare the way for analysis, but on the whole they go hand in hand, 

 first one step forward and then the other, as the parent teaches the 

 child to walk, until finally both run together. (Hann, Handbuch der 

 Klimatologie, Stuttgart, 1883.) 



Climate and agriculture. 



Friesenhof remarks, on the utilization of meteorology for agricultural 

 purposes, that this may be divided into the following sections: (I) Cli- 

 matology of the plants; (II) climatology of the region; (III) local me- 

 teorological knowledge ; (IV) weather predictions; (V) crop predictions. 

 Each of the five sections demands a special study, and a practical active 

 system of agrarian meteorology must carry them all on simultaneously. 

 One central station will not suffice to solve all the problems, but it has 

 its part to fulfill about as follows: 



I. The climatology of plants includes the sum of all climatological ele- 

 ments that influence their prosperity. The influence of each element 

 and of their most varied combinations must be studied; in other words, 

 an investigation of the relation of the plant to the climate wherever it 

 is cultivated throughout the world. This will require the following 

 meteorological data: The quantity and distribution of precipitation; 

 temperature, winds, cloudiness, insolation, and dew; these can be ob- 

 tained with sufficient accuracy from the records of the present meteor- 

 ological stations. 



II. The climatology of the region gives information as to the unequal 

 distribution of the individual meteorological elements in localities that 

 are comparatively near together. This is the special problem of agri- 

 cultural stations, and cannot be demanded of the central meteorological 



