124 Progress in Physics*. [January, 



afford, "judging by the experience of 106 well-marked instances of change 

 occurring at Falmouth during the first quarter of 1869, it is more unwise in the 

 ratio of io*o to 77 to be guided by the barometer, than to say off-hand that the 

 weather will continue as it has been." 



The interpretation to be placed on this apparently paradoxical statement is 

 clearly this. When we consult a barometer, we involuntary interpret its 

 changes with reference to the present appearance of the sky, the direction and 

 force of the wind, and ordinary local signs of weather. It is perfectly evident 

 that the use of the barometer by itself could scarcely fail to mislead us. 



Mr. Laughton read a resume of his work on " Physical Geography," noticed 

 in our last number. We did not then explain the agencies to which he attri- 

 butes the cause of atmospherical circulation. His views are concisely stated 

 in the following sentence : — 



" All observation shows us that there is not a permanent current (of wind) 

 towards the west, but that there is one towards the east ; and although we are 

 unable at present to master all the details of the manner of the motion, the 

 evidence of geographical fact, combined with that of astronomical possibility, 

 justifies us in inclining towards the belief that the motive force for which we 

 are seeking is really the disturbing force of the attraction of the heavenly 

 bodies." 



It will be seen that the proofs he adduces for the existence of the celestial 

 influence are not of a very convincing nature. 



" The Journal of the Scottish Meteorological Society" contains a continua- 

 tion of Mr. Buchan's discussion of the " Rainfall of Scotland." The district 

 treated of is that of the basins of the Forth and Tay, up to the line of the 

 Grampians. The average fall in the upper valleys of these rivers, in the West 

 of Perthshire, amounts to about go inches per annum, being 20 inches or 

 so more than that collected at Ettrick Pen, the wettest station in the south- 

 west of Scotland. This result appears to be attributable to the fact that the 

 mountains of Ulster drain the south-westerly winds which come to the south 

 of Scotland, while the Perthshire hills receive the air from the open Atlantic. 



The evidence against the dependence of the amount of rain upon mere height, 

 and in favour of its relation to local conditions, is very clear. Thus, for the 

 region about Loch Katrine, we find that " the absolutely largest average 

 obtained is 91*90 inches at Glengyle, which is only 580 feet above the sea. At 

 Loch Dhu, 325 feet high, the quantity is 87*62 inches ; whereas, at the Head 

 of Duchray Valley, 1800 feet high, the annual average is only 91*50 inches. 

 Even more striking is a comparison of the rainfall at Leng with that on the 

 west shoulder of Ben Ledi. At Leng, 345 feet in height, the annual quantity 

 is 66*37, whereas on Ben Ledi, at a height of 1800 feet, the amount is only 

 58*43 inches." 



Owing to the war, the foreign periodicals have not come in regularly. We 

 have only received the " Austrian Journal " up to July 15. The papers of most 

 interest in the latest numbers have been those on the climates of the Straits 

 of Magellan and of Bear Island. The first has been extracted from the 

 " Anales de la Universidad de Chile," and great credit is due to Dr. Hann for 

 having rescued it from its comparative oblivion. The observations were taken 

 at Punta Arenas, about the middle of the Straits, by Senor Jorje Schyte. 

 The following table of mean temperatures for the station, compared with those 

 for Dublin and Barnaul, in the corresponding latitude in the Northern Hemis- 

 phere, gives a fair idea of the cjimate : — 



Punta Arenas, Dublin, Barnaul, 



53°2' S. 53° 3 ' N. 53°3' N. 



Winter 35"4 2 •• 4 I *36 .. 0*14 



Spring 43'52 .. 46*22 .. 32*72 



Summer 50*54 .. 56*84 .. 64*04 



Autumn 42*62 . . 48*92 . . 32*18 



Year 42*98 . . 48*38 . . 32*36 



Range 16*90 . . 17*60 . . 72*00 



