9 8 



DYNAMIC METEOROLOGY AND HYDROGRAPHY. 



those of the Weather Bureau. But by a method of interpolation to be explained 

 below they have been reduced to simultaneousness with the others. Besides the 

 results of these kite ascents we have had at our disposal the synoptic charts of the 

 Weather Bureau for this day, but not the original observations from the stations at 

 the earth's surface. 



Table P contains for each of the kite-flights the calculated dynamic heights of 

 the three lowest standard isobaric surfaces (first column under each station), and 

 the mutual distances between these surfaces (second column under each station). 



Table P. Dynamic heights of standard isobaric surfaces and mutual distances between them, 



United States., September 23, i8g8. 



From the figures contained in table P and from the charts of the Weather 

 Bureau, the charts in figs. 13 and 14 have been drawn. The level curves used to 

 represent the absolute topography of the standard isobaric surfaces (fig. 13) are 

 drawn continuously where these surfaces run in the open air, while they are dotted 

 where they represent only the ideal continuation of these surfaces below the earth. 

 From a topographic chart the curves of intersection of the isobaric surfaces with 

 the earth (heavy curves in fig. 13) have been obtained. The curves representing 

 the mutual topography of successive standard isobaric surfaces are drawn con- 

 tinuously only as long as both surfaces run in the open air, while they are dotted as 

 soon as the lower surlace cuts the earth. The curves of intersection both of the 

 upper and the lower surface are drawn as heavy curves, and the portion of land 

 rising above the upper surface is shaded. 



The topography of the 1000 m-bar surface (first chart of fig. 13) is derived trom 

 the isobaric chart of the Weather Bureau, table 19 a of the Appendix being used as 

 explained in section 66. The charts of mutual topography (fig. 14) have been drawn 

 directly from the figures of table P. The situation of the kite stations is marked 

 on the first chart of fig. 13. In drawing the curves the observations from the two 

 stations North Platte and Dodge City, where the ascents came 6 to 8 hours too 

 late, have also been used, only with less attention given to them than to the others. 

 The chart of absolute topography of the 900 m-bar surface (second chart of fig. 13) 

 has been obtained by graphic addition of the first chart of fig. 13 and the first of fig. 

 14, and the chart of the 800 m-bar surface in the same manner by graphic addition of 

 the second of fig. 13 and the second of fig. 14. Afterwards they have been cor- 

 rected according to the absolute heights given in table P. As we have not had, as 

 already mentioned, at our disposal the original observations from the stations at the 

 earth's surface, we have refrained from every extrapolation from below. 



