628 



SCIENGM 



[N. S. Vol. VII. No. 175. 



articles of value to teachers, and that it is 

 now successfully entering on a second year. 

 The Journal has commended itself to the 

 Geographical Association of England, and 

 one of their members has been at their sug- 

 gestion appointed on the board of associate 

 editors. 



DUNES IN NORTH GERMANY. 



The drift plain of North Germany is in- 

 tersected by broad valleys, many of which 

 are the work of glacial rivers. Dunes are 

 common on the valley floors, and those 

 near the Elbe above Boizenburg are de- 

 scribed by P. Sabban (Die Diine der sud- 

 westlichen Heide Mecklenburgs * * * Mitth. 

 Meckl. Geol. Landesanst., VIII., Eostock, 

 1897). It is suggested that the dunes 

 were chiefly formed when the glacial waters 

 were withdrawn, leaving extensive barren 

 gravelly plains ; and that dunes, therefore, 

 do not indicate a period of dry climate. 

 Many of them are now more or less over- 

 grown ; some are forested, and one of these 

 is shown in an excellent plate. Small 

 dunes and sand deposits are found on the 

 uplands, where the sands are blown up 

 from the valleys. Mention is made of the 

 manner in which dunes shed water, so that 

 after a heavy rain they are wet to a depth 

 of only a few inches — a point to which 

 Shaler has called attention in this country. 



In this connection, it may be stated that 

 Keilhack reports an advance of about 9 

 meters yearly for several travelling dunes 

 near the Baltic coast (Jahrb. preuss. geol. 

 Landesamt. (1896), 1897, 194-198), giving 

 a good view of a heavy dune invading a 

 pine forest. 



W. M. Davis. 



CURRENT NOTES ON 3IETE0R0L0Gr. 



the gulf stream and the temperature 



of europe. 



Meinardus, in the Meteor ologisdie Zeit- 



schrift for March, finds a relation between 



the temperatures of the Gulf Stream waters 

 off the Norwegian coast and the tempera- 

 tures of central Europe, which relation he 

 expresses as follows : I. A high (low) 

 temperature in central Europe in the late 

 winter (Feb.-Mar.) and early spring (Mar.- 

 Apr.) usually follows a high (low) tem- 

 perature of the Gulf Stream off the Nor- 

 wegian coast in early winter (No v.- Jan.). 

 II. The greater the difference in pressure 

 between Denmark and Iceland in the pe- 

 riod September (or Nov.) to January, the 

 higher is the temperature of the Gulf 

 Stream and of the Norwegian coast in the 

 same months (Nov.-Jan.), and the higher 

 is the air temperature in central Europe in 

 the succeeding months (Feb. -Apr.). III. 

 The difference in pressure above noted has 

 only an indefinite relation to the tempera- 

 tures prevailing at the same time in central 

 Europe, and no relation to the tempera- 

 tures of May and June. 



atmospheric dust. 

 A series of interesting observations on 

 the 'dust' of the atmosphere is described 

 by Melander in a recent work ( ' Sur la 

 condensation de la vapeur d'eau dans 

 I'atmosphere,' Helsingfors, 1897), as noted 

 by Maurer in the Meteorologische Zeitschrifi 

 for March. The investigation was carried 

 on by means of the Aitken dust counter, 

 and included 3,000 observations in Finland, 

 the Sahara, and elsewhere. Some of the 

 results are as follows : The number of 

 dust particles increases with the dryness of 

 the air, there being usually a minimum in 

 the afternoon. Winds from the land carry 

 more dust than those from over the water, 

 and those blowing out of an anticyclone, 

 or down from high mountains, are very 

 dusty. Products of combustion furnish a 

 portiou of the dust particles which cause 

 condensation in the atmosphere. The im- 

 portant problem as to whether or not pre- 

 cipitation can occur without the assistance 



