September 1, 1888.] 



♦ KNOWLEDGE ♦ 



253 



KEY MAP TO THE SOUTHERN SKIES. 



HE accompanying map is intended for the 

 use of those who possess the series of twelve 

 Southern Maps which were completed in 

 Knowledge for January last. If a tracing 

 were made on sufficiently transparent paper, 

 this tracing placed over any one of those 

 maps would serve to indicjite where the 

 southern horizon, with the several points E., S.E., S., S.W., 

 and W., falls for the latitudes named. But a better plan is 

 for the observer in any of the latitudes mentioned to cutout 

 a piece of paper in the form of an arc, the up[)er edge of 



which corresponds to the pictured arc for that latitude. 

 Then having marked the above-named cardinal points along 

 it, he can bring the east and west ends of the arc to 

 coincidence with the points E. and W. on proper map for 

 the date and hour of observation. The stars seen in the 

 chart along and above that arc will then be the stars above 

 the horizon from east through south to west at the ob.server's, 

 station. 



Thus will the maps serve to show the stars over far 

 the greater part of the heavens visible from northern 

 latitudes, and all the stars visible in southern lati- 

 tudes from the equator to the most southerly inhabited 



