56 BIOGRAPHY. 



only can the observer watch from its shelter the habits of 



e. the various aquatic beings which frequent the lake, but 



can actually look into the nests built on the tops of lofty 



trees without the birds suspecting that their movements 

 could be seen. 



With regard to the decay of wood after it had been 

 felled, Waterton was not long in coming to the conclusion 

 that the " dry-rot," as it is oddly named, was caused not 

 so much by external moisture as by the natural sap of the 

 tree which had not been thoroughly expelled. When its 

 Dry-rot, juices have been completely dried and it is thoroughly 

 " seasoned," wood is as lasting as stone. We have in the 

 British Museum specimens of woodwork which, although 

 more than three thousand years have elapsed since the 

 trees were felled, are as sound as when they were first 

 carved. Waterton used to say that paint was the chief 

 cause of dry rot, especially when it was used to cover the 

 deficiencies of ill-seasoned wood, because it closed the 

 pores and did not allow the sap to escape. As a proof 



