CHAPTER XIII.

The Liquefaction of Chlorine Gas first effected by Mr. Faraday, and witnessed by the Author.--Sir H. Davy continues the investigation.--His paper on the application of Liquefiable Gases as mechanical agents.--Other probable uses of these bodies.--He proposes several methods to prevent the fumes which arise from Smelting-furnaces.--Importance of the subject.--His Letters to Mr. Vivian.--The Government solicit the advice of the Royal Society on the subject of protecting the Copper Sheathing of Ships from the action of sea-water.--Sir H. Davy charges himself with this enquiry.--He proposes a plan of protection founded on Voltaic principles.--His numerous experiments.--He embarks on board the Comet steam-vessel bound to Heligoland, in order to try his plan on a vessel in motion.--He arrives at Mandal, lands, and fishes in the lakes.--The Protectors washed away.--He teaches the inhabitants of Christiansand to crimp fish.--He remains a few days at Arendal.--A Norwegian dinner.--The Protectors are examined and weighed.--Results of the experiment.--The steam-vessel proceeds up the Glommen.--He visits the great waterfall.--Passes into Sweden.--Has an interview with the Crown Prince of Denmark, and afterwards with Prince Christian at Copenhagen.--He visits Professor Oersted.--He proceeds to Bremen to see Dr. Olbers.--Returns to England.--His third paper read before the Royal Society.--Voltaic influence of patches of rust.--A small quantity of fluid sufficient to complete the circuit.--He receives from the Royal Society the Royal Medal.--The Progress of Voltaic discovery reviewed.--The principle is of extensive application.--The Author's researches into the cause of the solution of Lead in spring water.--An account of the numerous trials of Protectors.--Failure of the plan.--Report of the French on the state of the protected frigate, La Constance.--Dr. Revere's new plan of Protection 208