PHILOSOPHICAL SOCIETY OP WASHINGTON. 89 



1859 of about 5 per cent., a return to the same value in 1873, and 

 then a decline, very largely augmented in 1815 and 1876, and 

 reaching a minimum price in July, 1876, of about 79 per cent., 

 compared with the relative value in 1845-50, being a decline of 

 21 per cent, from that value. From that point, however, it has 

 again advanced, so that at the present time the relative value of 

 silver to gold is only 10^ per cent, below that of 1845-50. 



Mr. Emil Besskls made a communication on 



THE LATE ENGLISH POLAR EXPEDITION, 



showing the positions reached, the temperatures, limits of ice and 

 open water observed, and comparing them with the results of other 

 expeditions. He demonstrated that the meteorological features 

 exhibited at the winter-quarters of the Englishmen were anoma- 

 lous, and gave some results of investigations unpublished yet, 

 being on the change of the temperature of the aif with the lati- 

 tude. He dwelt especially on the tides, stating that the tidal 

 wave reaching the winter-quarters of the "Alert" and "Discov- 

 ery" is not the Pacific wave, as stated in the report of Captain 

 Nares, but one of different origin. 



Mr. Dall stated that, if the assertion of Houghton, who had 

 examined the tidal records of the English exploring vessels at 

 Point Barrow, was correct, the tides there were of a simple semi- 

 diurnal character and quite different from those of Behring Sea 

 or of the northwest coast of America. Pie considered it probable 

 that the Arctic basin to the westward of the Parry Archipelago 

 has a tide of its own, which, however, was not to be confounded 

 with that experienced by the Arctic explorers to the eastward, 

 and which Dr. Bessels had very clearly shown to be derived from 

 the North Atlantic wave, and in all probability propagated 

 around the northern coast of Greenland. The speaker considered 

 it as almost certain that no tidal wave was propagated northward 

 through *the shallow strait of Behring; particularly as tlie obser- 

 vations at St. Paul Island and in Norton Sound indicated that 

 Behring Sea itself has a peculiar tide which is distinct from that 

 observed to the southward of the Aleutian Islands. 



