Geographical Maps and Sailing Charts. 



257 



points. Notwithstanding these relations and the facility with 

 which all necessary intersections may be determined by methods 

 of projection, as generally recommended in treatises on the 

 stereographic projection, in practice it will be found that 

 measurements derived from tables, as suggested, will make the 

 work not only much easier, but, what is of far greater import- 



Stereographic Map of the Western Hemisphere. 



ance, more accurate. By making use of the graphical methods, 

 described by the writer in a previous communication, the net- 

 work of meridians and parallels may be constructed in a 

 remarkably short space of time ; in fact, this projection, though 

 seemingly more complicated, is scarcely more so than the one 

 made on the plane of the equator, figure 4. 



Attention is invited to a comparison between the shapes of 

 the continents as they appear on the maps, figures 8 and 9, 

 and on a globe, when the latter is turned so as to show the 



