METEOROLOGY. ,'^'0 



hind and above a low center the movement in the npper regions is for 

 Sweden ordinarily from north or west, but there are cases in which the 

 movement is from south or southeast, which latter is the ordinary case 

 in England, according to Clement Ley. 



4. The temperature in the maxima and minima areas is above the 

 mean if the gradients incline towards the west, and below the mean if 

 inclined towards the east; in winter the temperature is above its mean 

 minimum and below in the maximum area ; in summer this is reversed. 

 The temperature differences between u])per and lower stations are great- 

 est when the gradient is directed towards the north or east, but least 

 towards the south or west. 



5. The quantity of clouds or rain are greatest for gradients towards 

 the south or west and least towards the northeast. 



6. The transparency of the air for distant objects is independent of 

 barometric pressure; greatest fog occurs with gradients towards the 

 west, but in the Kattegat the fog is most frequent for gradients towards 

 the north. {Z. 0. G. J/., xix, p. 4G9.) 



325. Prof. P. Busin, of Rome, has endeavored to indicate the various 

 positions that areas of high and low pressure must have relativeto Italy 

 in order to produce any given type of weather; he computes anew kind 

 of wind rose for Rome, showing the probability of various types of 

 weather for numerous relative positions of the isobars; the number of 

 these types may amount to about 100. He concludes that the changes 

 in the barometer for intervals of more than eight hours, and equally so 

 the changes of temjjerature for twenty-four hours, are of little use for 

 weather predictions ; he suggests that it will be probably of more use to 

 study the departures of the temperature and pressure for the normal 

 values of the day and the hour for which the weather map is drawn. 

 {Z. 0. G. il/., XIX, p. 235.) 



326. [The actual pressures and temperatures and the dejxirtures have 

 each their special significance — both are used by the Signal Office, but 

 of the two the former has greater value in studying the mechanical laws 

 of atmospheric motions.] 



327. Dr. J. van Bebber, of Hamburg, reviews the works of Hoffmeyer 

 and Teisserenc de Bort, as well as Hildebraudsson, on types of weather, 

 and their connection with general distribution of tem])erature and press- 

 ure. In conclusion he says: "If we glance back upon the progress 

 made in these [and his own equally extensive] works we must come to 

 the conclusion that the prevailing character of the weather on any day 

 in Germany is determined by the more general distribution of weather 

 conditions, and that we shall only understand the general weather 

 changes when we take into consideration the seasonal interchanging of 

 the general centers of action in the atmosphere. But within this region 

 [Europe] rapidly progressing changes are completed that can indeed 

 have no important influence on the ijrevailing weather of the larger 

 areas but that are of fundamental importance for the weather of small 



