METEOROLOGY. 303 



IV. — (o) Constitution of the atmosphere; (6) General physical 



PROPERTIES OF THE ATMOSPHERE, THE OCEAN, THE LAND. 



161. E. Rogovski offers to the Jounuil of the lliissiaD Clieiiiical and 

 Physical Society a mathematical and physical study ou the structure of 

 the atmosphere. He thiuks that the ordinary formulae can be used up to 

 10,000 meters, but above that the constitution varies with the height, 

 the proportion of oxygen diminishing, and at the height of 1,000 kilo- 

 meters the density is nearly zero. {Nature, xxx, p. 118.) 



162. A. L(5v3', of the observatory at Montsouris, has conducted a daily 

 series of observations on the chemical constituents of thi; atmo'sphe , 

 of which Prof. E. VVollny gives a brief summary : 



1. Ozone. — The average weight in milligrams per 100 cubic meters is 

 1.9 for 1877 ; 1.5 for 1878; 0.8 for 1879 ; O.G for 1880. The quantity of 

 ozone with southerly winds is very large; that with northwest to north- 

 east winds, quite small. 



2. Ammonia. — The average quantity of ammonia in milligrams per 

 100 cubic feet is as follows: 3.2 for 1877; 1.8 for 1878; 2.1 for 1879; 

 1.8 for 1880. The quantity of ammonia in the warmer half of the year 

 is sensibly greater than in the colder half. It also varies very much in 

 different localities near the observatory. 



3. Organic nitrogenous substances. — The average quantity was 0.6 

 milligram per 100 cubic meters. The deviations therefrom were too 

 small to recognize any material changes. 



4. Carbonic acid gas. — The average for the whole period was 30.2 

 liters per 100 cubic meters. The variations in the quantity of carbonic 

 acid are quite considerable, but probably no more than in similar meas- 

 urements by other observers. {Z. 0. G. 21., xviii, p. 380.) 



163. Miintz and Aubin have invented a very accurate method of de- 

 termining the quantity of carbonic gas in the atmosjihere, and have 

 taken a series of detertninations.at the summit of the Pic du Midi, at a 

 height of 2.877 meters. They find that the average at this altitude is 

 2.80 parts in 10,000 by volume, and at intermediate altitudes they ob- 

 tain the same result, showing that the gas is uniformly distributed 

 throughout the atmosi)here. {Z. 0. G. M., xvii, p. 25G.) 



164. Miintz and Aubin have presented to the Paris Academy of 

 Sciences the results of observations made on a uniform plan under 

 their directions in various parts of the world on the quantity of car- 

 bonic gas in the air. Their method consisted generally in making care- 

 ful analyses at the seven stations occupied by the French expeditions 

 for the observation of the transit of Venus; they also secured from 

 each station a series of glass vessels tilled with sami)les of the aii-, all 

 of which were analyzed at Paris by the authors. It is easily seen that 

 the i)r()p()rtion of carbonic gas is not very different at tliese stations and 

 at Paris, and that the variations everywhere depend on the condition 

 of the sky and the velocity of the wind; the general mean is 2.78 in 



