VISION UNDER WATER. 



J53 



XIII. 



Farfhsr Remarks and Experiments on Vision lender 

 Water. In a second Letter from a Correspondent : 

 with some Observations in Reply. By the Edi^ 

 tor, 



London Institution^ Sept. 17, 1806. 



To Mr. Nicholson* 

 Sir, 



JL II AVE to thank you, (before I make any further re- introduction. 



marks on the Paper in your 58th number, ''On the 



Art of Swimming,") for the insertion of my letter in 



your 60th Journal, and for the candid manner in which 



you were willing to investigate, whether my objection to 



what you therein stated was founded on fact. 



I have in consequence of your reply been induced to in the first wri- 

 make some actual experiments, since I had the pleasure ting of W. N. 

 of reading the account of those, which, together with your gubiect as if It 

 two friends you had made. I will presently state them were Impossi- 

 toyou, and they will, I think, clear your mind of every ^^^^^^°/^^''"*^^^ 

 doubt that can be entertained on the subject ; permit me 

 however first to revert to the Paper in which you diiTer 

 in opinion with Dr. Franklin — your words are these, 

 '' I am rather surprised at the Doctor's direction about 

 the egg, and the eyes open under water, because it seems 

 as if he thought the submerged experimentalist could see 

 the egg." • You after that say you must refuse your cre- 

 dit to such assertions, and add that '' Experiment will 

 easily clear up thematt*er to those who know nothing of 

 optics." You then state your unsuccessful attempt to 

 pick up your buckle in five feet water at Joanna, your 

 experiment at Harlei^ follo\Vs, and your conclusion is 

 thus drawn in your own words. " Whe;ice it appears, 

 thq,t all the stories of wonderful divers who could descend 

 into the sea and bring up small objects, such as jewels and 

 trinkets must be considered as tiibulous." 



On your reply to my letter, I have to remark, that the Objections to 

 (ylindrical glass ve>;3el, with which you made your ex- ^J^^^ ^^^'j^^ 



Vol.. XV. — Oct. 1806. X perimcnts 



