THE ELK-YARD. 131 



instead of erecting lofty walls and stately towers, the military 

 engineer sinks his buildings as far as he can into the ground, 

 and protects them with banks of simple earth, which is found 

 to be the best defence against heavy shot. There is no 

 masonry in existence that will endure the artillery fire of the 

 present day, and even the solid rock can be knocked to pieces by 

 it. But an earth-mound is a different business, and will absorb 

 as many shot and shell as can be poured into it, without being 

 much the worse for it. See, for example, the Proof-mound at 

 Woolwich, which receives the shot of guns as they are being 

 proved. Now, this mound has undergone perpetual battering 

 for many years, and is as strong as ever. The same thing may 

 be said of the celebrated Mamelon before Sebastopol. 



So much for the Fort made by the hand of man. We now 

 come to that which is formed by the feet of animals. 



The Elk, or Moose, an inhabitant of Northern Europe, finds 

 itself in great danger during the winter, the wolves being its 

 chief enemies. At certain times of the year there comes a 

 partial thaw during the day, followed by a frost at night. The 

 result is, that a slight cake of ice forms on the surface of the 

 snow, too slight to bear the weight of so heavy an animal, and 

 strong enough to cut the legs of the elk as it ploughs its way 

 along. Now, the wolves are sufficiently light to pass over the 

 frozen surface without breaking it, and accordingly, they can 

 easily run down and secure the elk. 



In order, therefore, to counteract the wolves, a number of 

 elks select a convenient spot where they can find food, and 

 unite in trampling the snow down so as to sink themselves 

 nearly to their own height below its surface. The wolves never 

 dare attack an Elk- yard, as this enclosure is termed. In the 

 first place, they are always haunted with suspicions of traps, 

 and do not like the look of the yard ; and in the next place, if 

 some of the wolves did venture within the fort, the elks would 

 soon demolish them with hoofs and horns. One of these Elk- 

 yards is seen on the left hand of the illustration. 



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