274 



PLATE CLIV. EARTH SHADOWS. 



From a pencil sketch made during the 'Discovery's' stay in M'Murdo Sound. 

 Aug. 1903. 



The sketch represents a remarkable shadow which appeared on a thin alto- 

 stratus of cloud in the southern sky for several mornings in succession, at the time 

 when the sun was just appearing or disappearing in the N. While the sun in the 

 N. apparently moved from E. to W., three beams of shadow, radiating from a point 

 in the horizon, followed one another in the S., moving from W. to E. 



The sketch represents the moment when these three shadows happened to be 

 arranged symmetrically. 



The most probable explanation is that they are really divergent, though, 

 from their immense length, apparently convergent, shadows, thrown on the sky by 

 Mounts Erebus and Terror, which lay behind the observer, between his back and 

 the sun. 



