SECRETARY'S REPORT. 147 



English, but that it is, on the whole, weaker and less durable; 

 and this opinion is sanctioned by a large number of English 

 writers. The question has not been fully settled by facts ; for 

 some of those who have expressed such an opinion in strong 

 terms conclude by admitting that, after all, American vessels 

 might be no less durable than English, were their timber 

 equally well seasoned. 



The white oak was largely employed in the frame of our 

 favorite frigate, which was built nearly sixty years ago. In 

 the course of the very thorough repair to which that vessel 

 was subjected about fifteen years since, many of the white oak 

 timbers of her frame were found in excellent condition ; and 

 it was stated on the best authority that in several instances 

 timbers of this description were sound, while others by their 

 side, of the southern live oak, had decayed. 



Now, the superiority of the live oak, in point of durability, 

 over the oak of any other country has never yet been ques- 

 tioned. The English oak, however, if really superior, could 

 be easily multiplied in our Northern and Middle States. It 

 has been already introduced, and some fine specimens of more 

 than twenty years' growth may be seen in our neighborhood. 



The timber generally selected for ship building is what is 

 called the pasture oak. This is greatly preferred to that 

 which grows in crowded forests, where the trees, from their 

 vicinity to each other, are robbed of much of the nutriment 

 which they derive from the soil, as well as of the genial influ- 

 ence of the sun and air. Hence the building of a single large 

 vessel requires the timber of many acres ; and as the white 

 oak is constantly felled in great quantities, both for home con- 

 sumption and for exportation, the period cannot be distant 

 when serious difficulty will be experienced in procuring a sup- 

 ply of this valuable wood. 



In this connection it may be proper to make one or two 

 remarks on the felling of trees. It is generally agreed that 

 the durability of timber depends materially on the season 

 when this operation is performed ; but what that season is, is 

 a question on which directly opposite opinions are held by the 

 ablest writers. The principal cause of the decay of wood of 

 all descriptions is thought to be the sap which remains after 



