220 DESTHOVERS OF SUBMERGED WOOD — MURPHY. 



Reasoning thus and wishing to try the experiment sug- 

 gested, I had four piles constructed from hemlock and spruce 

 boards. They were formed, first, by a core 4x4 in., and then 

 by boards prepared through submergence in a bath of coal tar, 

 then securely fastened, one by one, until the built pile attained 

 the dimensions of 12 x 12 in. The piles were then hooped and 

 shod with iron, and were driven, close to the Little Bras d'Or 

 brido-e, at one of the outlets of the Bras d'Or lakes (tidal waters) 

 Cape Breton. These piles, so formed, could well stand driving 

 under a 10 cwt. pile hammer. They were placed in posi- 

 tion in November, 18S9, and examined in September, 1890. 

 The teredos had completely riddled the outer board and in some 

 instances had entered the next board to it. 



In July, 1891, they were again examined, when they were 

 found to have penetrated to the third board, the two outer 

 boards having been destroyed and the third perforated. I exhibit 

 a section of the pile. You will notice that the outer board is 

 completely eaten away, scarcely any part of it being thicker than 

 a leaf of packing paper. You can by merely an impress of the 

 fingers rub it oft" in small leaflets. Still, it is evident that it was 

 partially, if not totally, destroyed at the point where the entry 

 was made to the second board before the entry was effected. In 

 like manner the second board was destroyed before an entr^^ at 

 assailable points to the third was effected. 



In the same place, not 100 yards from where these experiments 

 were tried, creosoted piles obtained from Messrs. Eppinger & 

 Russell, Brooklyn, New York, have been driven for over five 

 years, and there is not yet the slightest sign of a teredo having 

 entered any one of them. Essential oil of creosote impregnated 

 into such woods as are adapted to the purpose and treated in 

 such manner, as is being done by Messrs. Eppinger & Russell, 

 will, in my opinion, assure a long duration. 



The Teredo re([uires a clear, pure, salt water. It has often been 

 remarked, that piles placed in dirty muddy water or in the 

 neighbourhood of sewerage discharge are exempt from its attack. 

 From these observations one is led to believe that where there is 



