INDUSTRIAL PROGRESS DURING THE YEAR 1876. xxxvii 



Dr. Hellmann has contributed a discussion of the observations 

 made by the Army Signal Office at Mount Washington. He finds 

 the diminution of temperature with altitude agrees nearly with that 

 prevailing in Central Europe, The diminution is most rapid with 

 northw^est winds, and least rapid with southeast winds. 



In a review, by Caspari, of a rare work, by Isaac Vossius, " De motu 

 Marium et Ventorum," publislied at tlie Hague in 1663, it is claimed 

 that Vossius was the first to definitely promulgate the rule that it is 

 the rising and falling of the barometer, and not simply its absolute 

 height, that should guide us in predicting the weather. 



Considerable light has been thrown upon the formation and activ- 

 ity of ammonia in the atmosphere by the works of Schloessing and 

 others, according to whom the direct assimilation of simple gaseous 

 nitrogen by plants, and the emission of ammonia, is not admissible. 

 The formation of ammonia is by them attributed to the chemical ac- 

 tion of ocean water upon the nitric acid carried into it by rain and 

 rain-water. 



The efi'ect upon the barometer of any movement in the air is de- 

 duced by Montigny from observations in the tower of the cathedral 

 at Anvers. He concludes that the barometric pressure diminishes 

 less rapidly during west winds, and most rapidly during east winds. 



Ley finds that of 800 storms passing near Great Britain during 

 nine years, the large majority had a tendency to move in directions 

 parallel to the trend of the steepest gradients ; thus when the iso- 

 bars are closest on the southeast side, the tangents irend toward the 

 northeast, and fiftj^-five per cent, of these storms move in the same 

 direction. He finds also evidences of a less important disturbing 

 force tending to make the depressions move toward the northeast by 

 east. It would be interesting to compare Ley's rules with the be- 

 havior of American storms. We can see no reason why they should 

 obtain for the storms occurring between the Rocky Mountains and 

 the Atlantic coast. 



Blanford, of Calcutta, has published a memoir on the winds of 

 Northern India, which is a very fine example of inductive reasoning. 

 His object has been to describe normal wind-currents of Northern 

 India and their annual variations, and to trace out their origin and 

 causes in so far as these can be discovered in the local physical 

 changes in the atmosphere. These causes are, of course, found in 

 the variable moisture and heat, and the peculiar topography of India, 

 Very well drawn charts are given, showing the relation between the 

 movements of the winds and the clouds, 



Mr, Blanford's conclusions with regard to the origin of the cy- 

 clones of the Bay of Bengal apparently accord best with what we 

 know of similar storms elsewhere, " They form, in a region of calms 

 or variable winds ; an area of barometric depression and rising tem- 

 perature is formed several days before the cyclone is generated ; cur- 



