regard to its Defence. 217 



may be at least 6 inches thick, that being the depth to which 

 a miisket-ball penetrates in fir. In order to resist artillery, 

 two rows of similar trees are placed vertically in the ground, 

 with an interval of from 3 to 6 feet wide, which is filled with 

 earth well rammed. 



" The tiers or logs should be 11 or 12 feet long, so that 

 they may be planted at least 3 feet in the ground, and allow 

 the interior of the block-house to be 8 or 9 feet high ; it 

 should also be from 18 to 24 feet in the interior. 



" The earth used to render the covering shell-proof may be 

 formed like a small parapet, and from this an additional fire 

 of musketry may be obtained. I would here suggest that a 

 small pivot gun, say a 3-pounder, might be used from this 

 parapet, the pivot being stepped into the centre-prop of the 

 block-house." ( F«(i<? Plate III., fig. 1., the dotted lines.) 

 The text goes on to say, " The access to this upper parapet 

 is through a trap door in the roof. To prevent the block- 

 house fi-om being set fire to, a ditch should be dug round it, 

 leaving a basin of 8 or 10 feet ; and on this the earth is piled 

 up against the wood as high as the loopholes. 



" These works are sometimes constructed in the form of 

 cross, when the flanking fire thu« obtained renders them 

 more powerful. Sometimes they have an upper story, the 

 angles of which project over the lower story : the foot of the 

 lower walls may thus be defended by the fire from 

 above." 



Captain Macauley (page 149) says, "A block-house may 

 be constructed of less timber, by placing the upright timbers 

 6 or 8 feet apart against the interior slope, and covering them 

 with a capsill." {Vide Plate III., fig. k.) 



Captain Straith (page 377) thus describes American block- 

 houses : — " The Americans build their block-houses like 

 ordinary log habitations, of thick horizontal trunks of trees 



