1869.] Meteorology. 551 



amounting to • 3 inch below tlie mean of tlie year, and to • 5 below 

 the extreme monthly mean of that of May. At Glasgow the differ- 

 ence between the means of January and May amounts to only • 17 

 inch. Pressure in Iceland is most unsteady in February, and most 

 steady in July. 



We may here notice the discussion of the scientific results of 

 the German North Polar Expedition of last year, which has been 

 published by the Meteorological Office of Hamburg (the Nord- 

 deutsche See-warte). It appears from the meteorological observa- 

 tions that the large and unexpected accumulations of ice met with 

 by the ' Ger mania,' which had the efiect of preventing her reaching 

 the coast of Greenland, were in great measure connected with the 

 abnormally low mean temperature prevailing in high latitudes 

 during last summer. The mean daily temperature observed on 

 board the ship was 3^ * 5 F. lower than that which was due to her 

 geographical position. These facts afford a strong corroboration of 

 the views long maintained by Prof. Dove, viz. that there is a con- 

 stant compensation between the non-periodic variations in meteoro- 

 logical means. A warm season in any region is an indication that 

 in an adjacent district the weather is unnaturally cold. Oiu' readers 

 will not forget the great warmth of last summer (1868), and yet 

 during the whole of the period the temperature north of the parallel 

 of 70^ was unusually low. As regards the winds observed, the 

 general direction of their change was from N.E. through N. to 

 N.W., being thus in contravention of the law of gyration. Storms 

 were far more frequent from the N. and N.E. than from any other 

 quarter. The extraordinary prevalence of calms and of fog and 

 mist is also very noticeable. 



Deejj-Sea Temferatu7'es. — The paper, which is a report of a lec- 

 ture delivered by Herr von Freeden, at Hamburg, contains a long 

 discussion on the currents, &c., noticed during the voyage, and also 

 some notes as to deep-sea temperatures and their indications as to 

 submarine currents. As to the observations themselves, none go to 

 a depth greater than 170 fathoms, where a temperature of 33° was 

 recorded. The position assumed by the lecturer in interpreting the 

 observations is rather at variance with the ideas generally entertaiaed. 

 Herr von Freeden states that by recent observations in the open sea 

 it has been established beyond a doubt that salt water possesses a 

 maximum density at 39° • 5 F. In No. 22 of this Chronicle we 

 entered on this question at some length, but new light has since 

 been thrown on it. 



On the one hand, Prof. Miihry of Gottingen has published a 

 notice in the Journal of the Austrian Meteorological Society, in 

 which he states that having tried the experiment, he finds that salt 

 and fresh water have the same point of maximum density, and that, 

 accordingly, all deep soundings ought to show this temperature. 



