124 



PUKLIMINAKY WORKS. 



Turf (ly]<es are walls consti-iictcil of turf: tlicy can replace 

 stone walls, where turf is abundant and stones are rare ; at 

 the same tmie they are of a perishable nature. In the 



M^ 



/, jjMiMli^ 



Fig. 7. 



accompanying Fig. 7 (after J>iown) 'llie natural surface line 

 is represented by a, a, a, a, while b, 1/ are the places where 

 the turf has been excavated, and c, c, the dyke consisting of 

 successive layers of turf. 



3. W'dodiii I'aUiKj^. 

 There is an endless variety of wooden palings. 



I '^. ^:^ [^ r-a 



I I V V V V V V V V V I 



Fig. 8 shows a wooden fence, affording protection against 

 labbits on one half of the diagram. It sufTers under tlie 

 disadvantage thai all the upi'i.i^lit s))ars nnist be driven into 



