22c 



DYNAMIC METEOROLOGY AND HYDROGRAPHY. 



Table 19 A. Change of isobar ic charts, given in inches of mercury for sea-level, into charts of dynamic 



topography of the IOOO m-bars isobaric surface. 



Given the isobaric chart in inches of mercury and the isothermic chart, Fahrenheit, both for sea-level, the latter 

 reduced to sea-level under the supposition of a fall of temperature of i F. for every ioo dynamic meters of height. 

 On account of the smallness of the reductions no distinction between true and virtual temperature is needed. 



( 1 ) Required the level curve of height o on the iooo m-bars surface. The table shows this curve to be identical 

 with the isobaric curve of 29.53 inches pressure. 



(2) Required the level curve of height 250 dynamic meters on the 1000 m-bars surface, The table shows it to 

 pass closelv by the points of intersection of trie isothermic curve 50 F. with the isobaric 30.68 inches ; of the iso- 

 thermic 40"F. with the isobaric 30.6.5 inches; of the isothermic 30 F. with the isobaric 30.63 inches, and so on. 



(3) Required the level curve of height 50 dynamic meters on the 1000 m-bars surface. The table shows it to 

 pass closely by the points of intersection of the isothermic curves 50 and 40 F. with the isobaric 29.31 inches; 

 of the isothermic curves 30 and 20 F. with the isobaric 29.32 inches; of the isothermic curves 10, o, and +io 

 F. with the isobaric 29.33 inches, and so on. 



