108 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



It is probably thus that we explain the fact that the ratio 

 between the mean influence of the sun and the moon is, for 

 Fiume, 1.86, instead of its theoretical value, 2.55, as was to 

 be expected. The known effects of the tides at Trieste are 

 similar to those at Fiume. "J\riUheilun</e?i" Austrian Hy- 

 drograpkic Office, 1874, 723. 



THE DIURNAL AND ANNUAL PERIODICITY OF THE MOISTURE 



IN RUSSIA. 



Professor Wild, of St. Petersburg, has communicated an 

 extended investigation into the atmospheric humidity as 

 recorded at the Russian meteorological stations, a study 

 which may be looked upon as a continuation of his previous 

 memoir on the distribution of cloudiness in Russia. He 

 finds that the diurnal changes in relative humidity are in- 

 timately connected with diurnal changes in temperature, so 

 that a maximum of temperature coincides with a maximum 

 relative humidity, and vice versa. Furthermore, the am- 

 plitude of the daily oscillation in humidity has direct re- 

 lation to the changes in temperature. The diurnal changes 

 in absolute humidity have, however, a much less decided 

 connection with the temperature. The annual changes in 

 both absolute and relative humidity are given by monthly 

 means for forty-one stations. The annual changes in abso- 

 lute humidity may be directly connected with the tempera- 

 ture. The causes of the various annual changes in humidity 

 in different portions of Russia are explained by Wild in con- 

 nection with the seasonal distribution and changes of atmos- 

 pheric pressure and winds. Oesterreich. Zeitschrift Meteor- 

 ologie, X., 258. 



ON THE ACCURACY OF ANEMOMETERS. 



One of the most important and, at the same time, popular- 

 ly interesting matters relating to meteorology, or rather to 

 the mechanics of gases, is the relation between the pressure 

 and the velocity of winds; which subject, notwithstanding 

 the elaborate researches, both experimental and theoretical, 

 that have been made since the days of Lambert, is still far 

 from being satisfactorily resolved. The numerous experi- 

 ments seem uniformly to show that the measured pressures 

 of fluids against the surfaces opposed to them differs from 



