MATERIALS. 135 



So far as I am aware, the only satisfactory information on 

 this subject is that derived from a careful examination of various 

 kinds of timber which may have been in the sea for some con- 

 siderable time at the site of the proposed works. 



It cannot be argued that, because the worm is very bad or 

 does not exist in one place, similar conditions will be found 

 to obtain in another locality, although the two places may be 

 only a mile or two apart/ 



It would be well if those in charge of harbours or sea- works 

 would experiment with various kinds of timber, and make notes 

 periodically of their condition. By so doing, much useful infor- 

 mation might be gained respecting the sea- worms which infest 

 different localities, and the extent to which the various kinds 

 of timber suffer from their attacks. 



One word of caution as to the placing of the test-pieces. At 

 Holyhead it was found, in renewing creosoted timber, that the 

 Limnorice did not attack the new piles so long as old timber 

 remained for them to feed upon ; but when this was taken away 

 they were apparently driven to do so by sheer starvation. 



Similarly, in Algoa Bay (Cape Colony) I removed a long 

 timber jetty and other structures, in which a variety of woods 

 had been used as piles and bracings. These included creosoted 

 Baltic pine and greenheart. The creosoted timber was badly 

 eaten, both by Limnoria and Teredo, but the greenheart was 

 untouched, although it had been in the sea for many years. 



All the timber structures about the port having been re- 

 moved, others of iron were substituted. The fenders of these 

 latter were all made of greenheart, of excellent quality. Never- 

 theless, to the astonishment of everybody greenheart being 

 generally considered proof against the worm they were very 

 quickly attacked by the Teredo, etc., and in less than seven years 

 so badly were they eaten that in many cases they required 

 renewal. 



In view of the foregoing, it would appear desirable to keep 

 experimental pieces of timber of different kinds far apart from 

 each other, otherwise the worms may be attracted to those which 

 they prefer, and leave the others untouched, as was undoubtedly 

 the case in the instances which I have cited. 



Baltic Red-wood (creosoted), as has already been pointed out, 

 may with advantage be used in some localities. 



It is readily obtainable in logs up to 12 inches or 13 inches 



I 



