ON PREVENTING THE DECAY OF SHIPS. 03* 



IX. 



On the Causes of the Decay of the Timher in Ships, and the 

 J^jeans of preventing it. In ahetter from a Correspondent. 



To \VM. NICHOLSON, Esq. 

 SIR, 



T. 



HE advantages that England derives from her marine, Shi|)pjtir- «f 

 whether considered as appertaining to commerce or defence, gf^^*^ inponf 

 are too well known to need any comment; wjiatever then ^^q^j^jj.- ^^'^ ' 

 will contribute either to the safety or durability of the navy 

 becomes a matter of great public importance. 



The grand cause of the <^ecay of the timber employed in Cau5esof ihs 



building: of ships is the decomposition of its substances by °^^p' o^'^ie 



"- . "^ ^ . "' timber of, 



putrefaction, which is occasioned by moisture. This pre- 

 cautions and management may retard, but not prevent; 

 but a secondary one, the dry rot, may, I think, be both pre- 

 vented and eradicated. 



The dry rot, as it is usually called, proceeds from the jhe dry rot 

 growth of a parasitical plant, named by botanists bolettis known m verj 

 lachrymans, which belongs to the class of cryptogamia. Its ^ '^^^^^ umcs. 

 injurious tendency is mentioned as far back as liistory will 

 carry us, and the appearance and ravages are particularly 

 pointed out in the Bible*. The cure there directed is, to Remedies for 

 remove the materials injured ; and, if this did not stop the it. 

 disease, thej house was razed, and the entire articles of which 

 it was composed taken without the city. In latter times an 

 equally effectual but more easy remedy has been applied in 

 buildings, where this plant has taken root ; that of causing 

 a circulation of air in the parts affefted ; but this cannot be 

 introduced in the fabrics of which we are now treating. 



The fatal tendency of the dry rot in ships cannot be it$ jnj urious- 

 pointed out in a more forcible way, than it is in the memoirs "^^s to ite 

 of Pepys, who was secretary to the AdiBiralty during the 

 reigns of Charles the 2nd, and James the 2nd. At that 

 tiijie a consmission was formed to inquire into the state of 



• Lpviticns, Chap: I*. 



the 



