1856.] Durability of Timber— Ingenuity of Birds. 55 



DURABILITY OF TIMBER. 



The following iu stances show how extremely durable wood becomes, 

 when kept immersed in water. The piles under London bridge have 

 been driven six hundred and fifty years. On examination, in 1756, 

 they were found to be but little decayed : they were principally of elm. 

 Old Savory Place, in London, was built about the same time ; /. e„ about 

 six hundred and fifty years ago, and upon recent examination, the wooden 

 piles, consisting of oak, elm, beech, and chestnut, were found to be per- 

 fectly sound. 



But, the most striking example of the durability of timber in a wet 

 state, is afforded in the piles of the bridge built by i\iQ Emperor Trajan, 

 over the Danube. One of the piles was taken up, and found to be petri- 

 fied on the surface to the depth of about three-fourths of an inch : 

 beneath this the rest of the wood was not different from its original 

 state, though &ixteen hundred yrors had elapsed since it was driven 





INGENUITY OF BIRDS. 



Thrushes feed very much on snails, looking for them in mossy banks. 

 Having frequently observed some broken snail-shells near two projecting 

 pebbles on a gravel walk, which had a hollow between them, I endeav- 

 ored to discover the occasion of their being brought to that situation. 

 At last I saw a thrush fly to the spot with a snail-shell in his mouth, 

 which he placed between the two stones, and hammered at it with his 

 beak till he had broken it, and was then able to feed on its contents. 

 The bird must ha^'e discovered that he could not apply his beak with 

 sufficient force to break the shell when it was rolling about, and he 

 therefore found out and made use of a spot which would keep the shell 

 in one position. When the lapwing wants to procure food, it seeks for 

 a worm's cast, and stamps the ground by the side of it with its feet, 

 somewhat in the same manner as I have often done when a boy, in order 

 to procure worms for fishing. After doing this for a short time, the 

 bird waits for the issue of the worm from its hole, who alarmed at the 

 shaking of the ground, endeavors to make its escape, when it is imme- 

 diately seized, and becomes the prey of the ingenious bird. The lapwing 



