32G 



METEOROLOGY AND ALLIED SUBJECTS. 



views. Stewart then attempts to deduce some results from observations 

 in Europe by means of the method of indeterminate periods proposed 

 by Dr. Dodgson and himself. He finds that there is in three stations 

 out of four evidence of a nine-year period, and a still stronger evidence 

 of a twelve-year period, and makes some comparisons between the cor- 

 responding ten and twelve year periods in the daily amplitude of the 

 magnetic needle. {Z. 0. 0. M., XV, 1880, p. 228.) 



Fritz has i^ursued his further studies into the variations and height of 

 the water of the river Nile, and l*as added to his study of the records 

 of the Nilometer of the island of Ehodes, near Cairo, for the years 1825 

 to 1872, a further study of the records for the barrages for the years 

 1849 to 1878. The differences between the record at Cairo and the bar- 

 rages are quite sensible, amounting in extreme cases to 0.71 meter. The 

 extreme height of the river occurs on the dates shown in the following 

 table : 



Few rivers vary their regimen so regularly as the Nile, and the entire 

 periodical change reminds one forcibly of the interpretation of the 

 dreams, and the provisions against hunger and famine, that are attrib- 

 uted to Joseph, the son of Jacob. {Z. 0. G. M., XV, 1880, p. 302.) 



In a fourth contribution to the subject of secular variatious in the 

 weather, Koppen reviews a mass of data relating to the severe winters 

 of Europe during the past thousand years. He finds that regular laws 

 of periodicity, although they frequently a])pear to obtain for several 

 periods or centuries, yet eventually disappear and are replaced by 

 others. It is, therefore, impossible to base any predictions upon such 

 empirical periods, and he concludes that although he may have contrib- 

 butcd somewhat to our knowledge of the subject, yet his best result will 

 be the removal of any popular illusions in reference to this subject, and 

 the prevention of others from wasting time and labor. {Z. 0. G. M., 

 XVI, p. 194.) 



On the subject of the connection between barometric pressure and 

 sun-spot phenomena several contributions have been made. F. Cham- 

 bers has shown (1st) that similar non-periodic variations in pressure 

 occur throughout India and China, the epochs of maxima and minima 

 of pressure correspond to the minima and maxima, respectively, of sun 

 spots but fall behind these latter at intervals of six to thirty months, de- 

 pending on the longitude of the station, the western stations occurring 



