172 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



problem admit of; they differ, however, very much from 

 those of the method adopted by the Army Signal-Office. 

 His table is especially adapted to be used with the arith- 

 mometer of Thomas de Colmar. 



Dr. Woeikoff communicates to Petermann's Mittheilungen 

 some of the most recent results of the Russian Levelling Ex- 

 pedition into Siberia, under the command of General Von 

 Stubendorf. His results are considerably higher than those 

 previously accepted, and show us that the mean pressure in 

 the interior of Asia, when reduced to sea-level, is decidedly 

 higher than has been generally supposed. These results con- 

 firm his previously announced generalization that in northern 

 latitudes the atmospheric pressure is higher over the conti- 

 nents than over the sea. This excessive pressure over the 

 continents he refers to the well-known fact that the conti- 

 nents are especially cold in winter, and, on the average, cold- 

 er throughout the year than the ocean; whence follows an 

 anti-cyclonic movement of the winds, and an excess of clear 

 sky and barometric pressure. 



The diurnal variation of the barometer, as deduced from 

 twenty years' photographic records, at the Royal Observato- 

 ry, has been communicated to the Meteorological Society of 

 London. 



Rykatcheff announces the existence of a third diurnal bar- 

 ometric maximum, which is especially evident between lati- 

 tudes 40 and 45 N. and in the month of January ; it occurs 

 at about one or two o'clock in the morning. In order to de- 

 tect its presence at any station, it is necessary to have actual 

 hourly observations throughout the night. It seems to be 

 equally obvious at stations in Europe, Asia, and North Amer- 

 ica, and does not exist in the tropics. 



In reference to a third daily barometric maximum, Kar- 

 linski writes that his twenty-five-year record at Cracow con- 

 firms Rykatcheff's announcement, but only for the month of 

 January, and even then only in the faintest trace. He adds 

 that from 52 to 87 averaging 70 barometric waves annual- 

 ly pass over Cracow. 



Linss, of Darmstadt, calls attention to the importance of 

 considering the inertia of the atmosphere (Lamont's theory) 

 in explaining the diurnal barometric variation. In studying 

 the direction of the motion of the clouds, he finds that the 



