INDUSTRIAL PROGRESS DURING THE YEAR 1874. X xxv 



tension eastward. That ocean meteorology will hereafter 

 receive much more attention than it has during the past ten 

 years is assured by the fact that the German government 

 has taken the important step of elevating the private See- 

 warte of Von Freeden to the rank of a national institution, 

 while Holland, Germany, and Russia have united in the or- 

 ganization of work relating to maritime meteorology ; and 

 the meeting held in September at London of the Maritime 

 Conference, called together by the permanent committee of 

 the Vienna Congress, passed such resolutions and recom- 

 mendations as will contribute decidedly to a unity of action 

 on the part of both naval and merchant services in Europe, 

 and we hope also in America. 



In the United States, an important change has been that 

 by which the reports of the voluntary meteorological observ- 

 ers of the Smithsonian Institution, the Patent Office, the 

 Agricultural Department, and official reports of the Surgeon- 

 General's office of the Army, and to a considerable extent 

 those of the Navy, have all been concentrated at the Weather 

 Bureau of the Army Signal-office; as a consequence of which 

 its monthly weather reviews have acquired a greatly in- 

 creased value, being now based upon nearly five hundred 

 stations. From these weather reviews we gather that, on 

 the average, about twelve storm-centres pass monthly over 

 some portions of the United States. 



Of special investigations in this department of science, we 

 notice the great work of Koppen on the remarkable connec- 

 tion between increase or decrease of solar spots and the 

 changes of temperature throughout the earth; the investiga- 

 tion by Mohn into the anomalies in the diminution of tem- 

 perature with increasing altitude; and the valuable studies 

 of Miihry into the distribution of moisture in the upper 

 strata, showing that a stratum of saturated air exists at a 

 certain altitude over the greater part of the earth. 



Weilemann has shown that the protection against radiation 

 of heat from the earth afforded by the average cloudiness of 

 the sky is three times that afforded by the moisture present 

 in clear weather. Fines shows that the radiation during 

 clear nights is less in the city than in the country. 



The laws of the movement of storms have been elucidated 

 by Maydell, who has shown their tendency to follow areas 



