256 Sir Humphry/ Davy on the [April^ 



For a considerable space round the protectors, both on the 

 stern and bow, the copper was bright ; but the colour became 

 green towards the central parts of the ship ; yet even here the 

 rust or verdigrease was a light powder, and only small in quan- 

 tity, and did not adhere, or come off in scales, and there had 

 been evidently little copper lost in the voyage. That the pro- 

 tectors had not been the cause of the trifling and perfectly 

 insignificant adhesions by any electrical effect, or by occasion- 

 ing any deposition of earthy matter upon the copper, was 

 evident from this — that the lead on the bow, the part of the ship 

 most exposed to the friction of the water, contained these adhe- 

 sions in a much more accumulated state than that in which they 

 existed near the stern ; and there were none at all on the clean 

 copper round the protectors in the bow ; and the slight coating 

 of oxide of iron seems to have been the cause of their appear- 

 ance. 



] had seen this ship come into dock in the spring of 1824, 

 before she was protected, covered with thick green carbonate 

 and submuriate of copper, and with a number of long weeds, 

 principally fuci, and a quantity of zoophytes, adhering to differ- 

 ent parts of the bottom ; so that this first experiment was highly 

 satisfactory, though made under very unfavourable circum- 

 stances. 



The only two instances of vessels which have been recently 

 coppered, and which have made voyages furnished with protec- 

 tors, that I have had an opportunity of examining, are the Eliza- 

 beth yacht, belonging to Earl Darnley, and the Carnebrea 

 Castle, an Indiaman, belonging to Messrs. Wigram. The yacht 

 was protected by about .^i-j- part of malleable iron placed in two 

 masses in the stern. She had been occasionally employed in 

 sailing, and had been sometimes in harbour, during six months. 

 When I saw her in November, she was perfectly clean, and the 

 copper apparently untouched. Lord Darnley informed me that 

 there never had been the slightest adhesion of either weed or 

 shell-fish to her copper, but that a few small barnacles had once 

 appeared on the loose oxide of iron in the neighbourhood of the 

 protectors, which however were immediately and easily washed 

 off. The Carnebrea Castle, a large vessel of upwards of 650 

 tons, was furnished with four protectors, two on the stern, and 

 two on the bow, equal together to about -j-Jp^ of the surface of the 

 copper. She had been protected more than twelve months, and 

 had made the voyage to Calcutta and back. She came into the 

 river perfectly bright ; and when examined in the dry dock was 

 found entirely free from any adhesion, and offered a beautiful 

 and almost polished surface ; and there seemed to be no greater 

 wear of copper than could be accounted for from mechanical 

 causes. 



Had these vessels been at rest, I have no doubt there would 



