314 R. H. Hammer sley-Heenan^ C.E. — A Short [Nov. 28, 



The Chelura. and lAmnoria^ are much smaller than the Teredo^ 

 and perhaps, for that reason are not so much dreaded, but nevertheless 

 they are most destructive, and whatever they may lose in size they 

 make up in numbers. I do not think I have seen the latter in this 

 country. The former however is only too common, as I shall show 

 further on. The specimens marked " B " are a portion of a waling 

 destroyed by the Chelura. 



It is far beyond the range of my attainments to give anything 

 approaching a scientific description of these mollusca, as my know- 

 ledge of natural history is painfully limited, and even if it were not 

 so, no useful end would be served, for it would be difficult to deal more 

 fully with the subject than M. de Quatrefages has done. I have 

 however to make a statement which, if not scientific, is none the less 

 indisputably and painfully true, and it is this, " the Teredo and Chelura 

 work complete destruction in timber that is considered proof against 

 them," as I shall now endeavour to show. 



The Teredo navalis — as its name implies — has been the dread of 

 ship-builders in times past. And in Holland, and all over Northern 

 Europe the source of endless trouble, oak, pine, elm, and all other 

 kinds of timber then used in Europe succumbed to the ravages of this 

 pest and it was not until the year 1840, when greenheart was first 

 proved to be able to resist the worm in England, that timber could be 

 used with safety in any permanent marine works, unless it was first 

 protected with copper sheeting or scupper nails. 



The experiments with greenheart, made some fifty or sixty years 

 ago at Liverpool, having given satisfactory results, this timber at 

 once came largely into general use for marine works, and has since 

 been adopted by engineers in all parts of the world, and although 

 in some localities it has been attacked, still the damage was so slight 

 as to cause but little alarm, and greenheart continued to be considered 

 Teredo-YQBi&tir^^ timber. 



The sneezewood {Pteroxylon utile) of this country is another 

 timber that has long enjoyed a reputation of never having been 

 known to yield to the attack of the worm. I shall however have 

 to show in the course of this paper, that both timbers have, within 

 my experience, entirely failed to uphold the favourable reputation 

 they have so long held. 



About fourteen years ago the railway from Port Elizabeth io 

 Uitenhage was constructed by a private company, who decided 

 for various reasons to use timber extensively in the construction of 



