THE HEART OF THE ANTARCTIC 



the illustrations by algraphy, or printing from aluminium 

 plates. He had not got a proper lithographing press, 

 so had to use an ordinary etching press, and he was 

 handicapped by the fact that all our water had a trace of 

 salt in it. This mineral acted on the sensitive plates, but 

 Marston managed to produce what we all regarded as 

 creditable pictures. In its final form the book had about 

 one hundred and twenty pages, and it had at least assisted 

 materially to guard us from the danger of lack of occu- 

 pation during the polar night. 



