MATERIALS. 143 



The metal, as in the case of the Gambia's plates, was perfectly 

 sound and tough when worked up. 



The wrought-iron piles of a pier built by the late Sir John 

 Coode at Ramsey (Isle of Man), showed no sign of corroding 

 after a lapse of from eight to ten years. The original coating 

 of paint or black varnish was at that period in good condition, 

 and keeping the piles from rusting below low water, while above 

 low water it was easily maintained. 



The same remarks apply to a somewhat similar pier l which 

 I constructed at Port Elizabeth, under Sir John Coode's direction, 

 a year or two prior to the Ramsey pier being built. 



After a lapse of about six years, some of the piles were 

 examined under water, and on the removal of the sea-growth, 

 which adhered to them in large masses, the paint was found to 

 be undisturbed, and the piles free from rust. 



The iron work of a beacon which was removed. from the 

 Wolf Rock, after an exposure of thirty years to the corrosive 

 action of sea-water, was found to be in a good state of preser- 

 vation. It had been protected by a coating of red-lead paint, 

 which was renewed annually. 



Some of the internal cement rubble-filling was removed for 

 the purpose of affording space for the stowage of the workmen's 

 tools during the erection of the lighthouse, when the threads 

 of the screw-stays that were embedded in the cement were 

 found to be as perfect as when first made. 2 



In the discussion which followed the reading of Mr. Hooper's 

 paper on the New Ferry and New Brighton piers, at a meeting 

 of the Institution of Civil Engineers, Mr. Beardmore remarked 

 that there was nothing to be feared with regard to the question 

 of the decay of the iron in works of this kind under ordinary 

 circumstances, when reasonable care was taken. There had, 

 however, recently come under his notice the case of a sea-lock 

 which had existed for thirty-five years at the head of a ship 

 canal containing very soft water. When pumped out for repairs, 

 it was found that all the cast and wrought iron portions of the 

 gates, etc., were equally destroyed. Even the spikes of the 

 platform planking had perished, though the timber was perfectly 

 sound. He attributed that intense action of the water upon 



1 This pier was within a hundred yards of the wreck of the Gambia. 



2 Min. Proc. List. C.E., vol. xxx. p. 6. 





