46 



POLAR PROBLEMS 



Fig. 9 — Map of the poleward part of the northern hemisphere showing approximatelj' the existing 

 net of meteorological stations (based on publications of the United States, Canadian, Danish, and 

 Russian meteorological offices). Mean scale, i: 82,000,000. 



The stations are differentiated according to their method of disseminating reports: i, by wireless; 

 2, by telegraph; 3, by some slower method. All three types accumulate records of permanent climatolog- 

 ical value, whereas only stations of types i and 2 provide material for forecasting. Also, reports from 

 all the stations of these two types are not as yet available to all central forecasting offices, such as 

 London, Paris, or Washington. (On stations of type i see: Particulars of Meteorological Reports 

 Issued by Wireless Telegraphy in Great Britain and by the Countries of Europe and North Africa, 

 [British] Meteorol. Office Publ. No. 252, sth edit., London, 1927.) 



Title of Figs. 10-15 Contini'Ed — The only other published maps showing the distribution of 

 atmospheric pressure in the Arctic on consecutive days are, so far as known, the following — all for 1883, 

 being based on the observations of the international polar stations of 1882-1883: Feb. 1-2, by H. A. 

 Hazen (Hann's "Lehrbuch der Meteorologie," 4th edit., Leipzig, 1926); March 8-9, by H. A. Hazen 

 (A. W. Greely: Report on Proceedings of U. S. Expedition to Lady Franklin Bay, Vol 2, Washington, 

 1888); May 30-June 3 (E. Vincent: Sur la marche des minima barometriques dans la region polaire 

 arctique du mois de septembre 1882 au mois d'aoiit 1883, Memoires Acad. Royale de Belgique, Classe des 

 Sci., Series 2, Vol. 3, Brussels, 1910); March 1-5, April 8-12, April 17-20, May 7-10, June 4-7 (Das 

 Luftschiff als Forschungsmittel der Arktis: Eine Denkschrift, Internatl. Studiengesell. zur Erforschung 

 der Arktis mit dem Luftschiff, Berlin, 1924). 



