200 REPORT — 1861. 



Preliminary Report on the Best Mode of Preventing the Ravages of 

 Teredo and other Animals in our Ships and Harbours. By J. Gwyn 

 Jeffreys, F.R.S., F.G.S. 



Since the last meeting, Mr. Jeffreys vent to Holland for the purpose of 

 investigating the experiments which are being made there, under the direction 

 of the Academy of Sciences at Amsterdam, and with the sanction of the 

 Dutch Government, in order to check the destructive ravages of the Teredo 

 marina; and he was accompanied by Dr. Verloren, of Utrecht, another 

 member of the Committee. The progress of these different experiments is 

 periodically and carefully recorded ; but it will take many years before the 

 result can be shown. From an elaborate report of the Dutch Commission, 

 published last year, and which was placed by M. Van der Hoeven in Mr. 

 Jeffreys's hands, it appears that no efficacious remedy had at that time been 

 discovered. Even the expensive process of creosoting the timber failed in 

 one instance where the piece of wood thus treated was in contact with another 

 piece which had not been creosoted ; the Teredo having indiscriminately per- 

 forated both pieces of wood, first attacking the unrreosoted wood. Mr. Jef- 

 freys had also lately seen a piece of wood used in the construction of harbour 

 works at Scrabster, which, although it had been creosoted to the extent of 

 10 pounds to the square foot (having been first dressed and cut), was exca- 

 vated on every side by the Limnoria lignorum. Iron-headed or scupper nails 

 afford very little protection, as the Teredo and Lii^moria work their way even 

 through the rust, unless it is very thick, the valves of the Teredo becoming 

 stained in consequence. The remedy suggested by Mr. Jeffreys (viz. a coating 

 of some siliceous or mineral composition) had not been tried in Holland or 

 France. Among other communications received by Mr. Jeffreys on the sub- 

 ject was one from Mr. William Hutton, of Sunderland, who had recently 

 taken out a patent " for preventing the destruction of timber from the action 

 of marine animals." His process is to force into the wood a soluble silex, or 

 water glass, with muriate of lime. If this process is not expensive, it would 

 no doubt answer the desired purpose ; but it is probable that the same object 

 would be attained by merely soaking the wood in a solution of this kind, or 

 even laying it on the wood with a brush. It would seem to be sufficient if the 

 outer layer of the wood were coated or glazed in such a manner that the 

 composition would not crack or peel off. 



Although the different kinds of Teredo are locally and partially distributed 

 on our coasts, the wood-boring Crustacea (and especially Limnoria lignorum) 

 occur everywhere in countless numbers, and on the whole do the greatest 

 damage to our harbour works. Mr. Jeffreys endeavoured to obtain, through 

 a member of the Committee who resided at Plymouth, permission from the 

 Admiralty to institute some experiments in the Dockyard there, having been 

 informed that very considerable damage had been sustained in that port 

 during many years past from the last-mentioned cause. But, although a 

 copy of the Association's Proceedings was furnished to the First Lord and 

 Secretary to the Admiralty, and the Port- Admiral expressed his approval of 

 the experiments being tried, and forwarded the application to the Admiralty, 

 permission was refused. It does not appear that the Admiralty or Govern- 

 ment have taken any steps to prevent further loss, or even to inquire into the 

 matter. 



Notwithstanding this discouragement, Mr. Jeffreys will persevere, with the 

 assistance of the other members of the Committee, in doing all that is possible 

 to ensure such an important and national object as the protection of our ships 

 and harbours from the destructive attacks of these animals. 



