612 
5. Notice of the Ravages of the Limnoria Terebrans on Creo- 
soted Timber. By David Stevenson, Esq., F.R.S.E., 
M.I.C.E., &c. 
The author stated that it would be difficult to estimate the value of 
any chemical or mechanical process whereby timber might be ren- 
dered permanently impervious to the ravages of the Limnoria tere- 
brans, that small but sure destroyer of timber structures exposed 
to the action of the sea. 
The ravages of that crustacean were first observed in 1810 by 
Mr Robert Stevenson, the engineer of the Bell Rock Lighthouse, 
in the timber supports of the temporary beacon used by him in the 
erection of that work. Having forwarded specimens of the insect, 
and of the timber it had destroyed, to Dr Leach, the eminent Na- 
turalist of the British Museum, Dr Leach, in 1811, announced it as a 
“ new and highly interesting species which had been sent to him by 
his friend Robert Stevenson, civil engineer,” and assigned to it the 
name of Limnoria terebrans (Linnean Trans., vol. xi. p. 370, and 
Edinburgh Encyclopaedia, vol. vii. p. 433). 
The Teredo navalis , which was a larger and even more destruc- 
tive enemy, was happily not so prevalent in northern seas as the 
Limnoria. 
Experiments made at the Bell Rock by Mr Robert Stevenson, 
extending over a period of nearly thirty years, the detailed account 
of which was given in Mr Thomas Stevenson’s article on Harbours 
in the te Encyclopaedia Britannica,’’ had clearly proved that teak, Afri- 
can oak, English and American oak, mahogany, beech, ash, elm, 
and the different varieties of pine, were found sooner or later to 
become a prey to the Limnoria. Greenheart oak was alone found to 
withstand their attacks ; and even this timber was said in some in- 
stances to have failed. 
Mr Stevenson’s experiments also included the testing of the arti- 
ficial processes of Kyan and Payne, the former being an injection of 
corrosive sublimate, and the latter of proto-sulphate of iron. Tim- 
ber prepared by Kyan’s process was attacked in two years and four 
months, and in four years and seven months was quite destroyed. 
Timber prepared by Payne’s process was attacked in ten months, 
and destroyed in one year and ten months. 
