526 Institution of Civil Engineers. 



INSTITUTION OF CIVIL ENGINEERS. 



Nov. 27, 1849.—" A description of the Old Southend Pier-head, 

 and the extension of the pier ; with an inquiry into the nature and 

 ravages of the Teredo navalis, and the means hitherto adopted for 

 preventing its attacks." By Mr. J. Paton. 



After describing the form of construction of the old pier-head, and 

 showing the adoption of copper sheathing for protecting it from 

 decay, and the important considerations involved in the attempt to 

 preserve marine structures, the paper explained the ravages com- 

 mitted by marine worms {Teredo navalis, Limnoria terebrans, and 

 others) on the piles, both above and below the copper sheathingiJ 

 A general outline of the extension of the pier, and a minute descrip- 

 tion of the pier-head, were then given ; followed by an investigation 

 of the nature and operations of the Teredo navalis, which showed, as 

 a remarkable pecuharity, that no chemical means had hitherto pre- 

 vented wood from being destroyed by these animals and the Lim- 

 noria terebrans, whose destructive powers were likewise noticed, as 

 having penetrated between the copper sheathing and the wood at 

 Southend. The operations of the Teredo, although most destruc- 

 tive in warm climates, extended themselves to all places, having been 

 found almost in the Polar seas. The chief peculiarities which distin- 

 guished the Teredo were stated to have been ascertained by minute 

 microscopical investigation, and that woody fibres of an extremely 

 minute nature had been discovered in the body, thus setting at rest 

 the question as to whether the Teredo did actually feed upon the 

 wood. It was stated, that the failure of chemical means to preserve 

 timber from destruction by the marine worm was believed to proceed 

 from two causes, namely, of poisonous compounds having no seriously 

 injurious effect upon them, and the sea- water, and other things, de- 

 composing the poisonous ingredients contained in the wood. 



In corroboration of the first of these views, accounts of experi- 

 ments made by Mr. Paton were adduced ; and physiological facts, 

 quoted from the British and Foreign Medical Review, were brought 

 forward to show that cold-blooded animals were much more tenacious 

 of life than those of a higher temperament ; and hence it was argued, 

 that as it required a very large quantity of poison of the most virulent 

 nature to destroy animals of a much higher order than the Teredo 

 navalis, it would take a still greater quantity to affect those animals 

 as they existed in their own element ; and it was questioned, under 

 these circumstances, whether wood could ever be so completely and 

 thoroughly saturated as in any degree to affect them. 



The corrosive action of the sea- water, its extended influence and 

 constant variableness in diflferent parts of the globe, were then com- 

 mented on, and some of the various salts held in solution mentioned. 

 It was believed to be impossible to form any general notion of the 

 precise action of sea-water on timber, whether chemically saturated 

 or not, without a series of most minute experiments, and a large body 

 of facts carefully collected in different parts of the globe; as that 

 which might be advantageously used in the Thames might not be of 



