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APPENDIX. 

 The refults of the experiments made with Lord Charles 

 Cavcndifll's thermometer, and thofe with the bottle fitted 

 by Dr, Irving, differ materially as to the temperature of 

 the fea at great depths j I {hall give an account, there- 

 fore, of the precautions ufed by Dr. Irving to prevent the 

 temperature from being altered, as well as of the allowance 

 made by Mr. Cavendifli for compreffion, as they commu- 

 nicated them to me. 



The following is the account of the precautions taken 

 by Dr. Irving to prevent the temperature of the water 

 being changed in bringing up from the bottom ; 



** The bottle had a coating of wool, three inches thick", 

 " which was wrapped up in an oiled Ikin, and let into a 

 " leather purfe, and the whole inclofed in a well-pitched 

 " canvafs-bag, firmly tied to the mouth of the bottle, fo 

 " that not a drop of water could penetrate to its furface. 

 " A bit of lead ftiaped like a cone, with its bale downwards 

 " and a cord fixed to its fmall end, was put into the bottle ; 

 " and a piece of valve leather, with half a dozen flips of 

 " thin bladder, were ftrung on the cord, which, when 

 "pulled, effedually corked the bottle in the infide." 



The 



