FIELDS OF PRESSURE AND MASS IN THE ATMOSPHERE. 



io5 



On November 7, 190 1, in the morning and forenoon there ascended* from Paris 

 one registering balloon with two instruments; from Strassburg two registering and 

 one manned balloon; from Berlin two registering and one manned balloon; from 

 Vienna one registering and two manned balloons. From St. Petersburg one reg- 

 istering balloon ascended on the following morning, November 8. This ascent has 

 been treated as simultaneous with the others, our aim being only to exemplify the 

 technics of our methods, not to discuss the true state of the atmosphere on this par- 

 ticular occasion. 



Table R. 



-Dynamic heights of standard isobaric surfaces and mutual distances betxveen them, 

 computed from ascents, Europe, November 7, 1901. 



The results of these ascents have been worked out according to the methods 

 developed in the preceding chapter. In cases where two or more balloons have 

 ascended from the same place, the observations from all the ascents have been 

 introduced in the same diagram and the curve of virtual temperatures drawn so as 

 to suit all observations as closely as possible, attention being paid to the different 

 observations in proportion to their probable value. Thus as long as observations 

 from manned balloons are available, the curve is drawn through points representing 

 these observations. The distance of the observations of the registering balloons 

 from this curve gives valuable corrections to the records of the registering balloon, 

 which may be applied for the greater heights not reached by the manned balloons. 



Table R contains the results of the ascents worked out as absolute heights of 

 the standard isobaric surfaces and as distances from surface to surface, while table 

 T contains the same results in the form of absolute pressures at standard levels and 

 differences of pressure from level to level. 



* Publications de la Commission Internationale pour l'Aerostation scientifique. Observations des ascensions 

 internationales simultanees et des stations de montagne et de nuages 1901, pp. 390-410. Strassburg, 1903. The use 

 of this important publication is very much impeded by the fact that the observations taken at the common meteor- 

 ological stations on the days of the ascents are not accessible till many years afterwards, according as the meteor- 

 ological year books of the different countries appear. This circumstance has forced us to choose our example from 

 the first year of the international ascents, when the aeronautical stations were less numerous and the self-registering 

 instruments less trustworthy than they are at present. 



