72 



PHILOSOPHICAL TRANSACTIONS. 



[anno 1757. 



No. 



1.. . 

 2... 

 3... 

 4... 

 5... 

 6... 

 7... 

 8... 

 9.-. 

 10... 



Heights 



Wt. 



Ft. In. 



6 2 

 ,5 

 .5 

 .5 

 .5 

 .5 

 .5 

 .5 

 .5 

 .5 



Pds. 



161. 



10| 147. 



9J 156. 



6i 140. 



5^ 158. 



5i: 158. 



4| 140. 



3^ 132. 



4^ 121. 



34- 146\ 



Ht. Water 



before 

 immersed 



Inches. 

 . . 19 30. . . 

 ..-19.25... 

 ..19.21... 

 ..1917... 

 .. 19.13.. . 

 ..1909... 

 .. 19.05... 

 .. 19.01... 

 ..18.97... 

 ..18.93... 



Ht. Water 

 when 



immersed 

 Indies. 



..21.'20. . 



..21.16. 



. .21.06.. 



..21.21. 



..21.21. 



..21.26. 



..21.06. 



. . 20.86. 

 , . . 20.76. 

 . . . 20.66. 



Water Weight 



raised. Water. 



Solidity. 

 Inches. Pounds. 



. 1.90 2.573 160.8 



.1.91 2.586 161.6 



.1.85 2.505 156.6 



.2.04 2.763 172.6 



.2.08 2.817 176.0 



.2.17 2.939 183.7 



.2.01 2.722 170.1 



.1.85 2.505 156.6 



. 1.79 2.424 151.5 



. . 1.73 2.343 146.4 



One of the reasons, that induced Mr. R. to make these experiments, was a 

 desire of knowing what quantity of fir or oak timber would be sufficient to keep 

 a man afloat in river or sea water, thinking that most men were specifically 

 heavier than river or common fresh water ; but the contrary appears from these 

 trials: for, excepting the first and last, every man was lighter than his equal bulk 

 of fresh water, and much more so than his equal bulk of sea water: conse- 

 quently, could persons, who fall into the water, have presence of mind enough 

 to avoid the fright usual on such accidents, many might be preserved from 

 drowning ; and a piece of wood, not larger than an oar, would buoy a man 

 partly above water so long as he had spirits to keep his hold. Some things 

 herein advanced will perhaps more readily appear from the following relation. 



The Lords of the Admiralty have appointed, for the exercise of the scholars 

 belonging to the royal academy at Portsmouth, a small yacht ; wherein, during 

 the suirimer months, those young gentlemen are taught the practice of working 

 a vessel at sea, under the directions of one of the master-attendants, assisted 

 by 8 or 10 seamen. The last time this yacht was out, which was about the 

 beginning of last October, one of the scholars was ordered to heave the lead. 

 The youth was about 13 years old, small of his age, and far from being fat ; as 

 he was stepping on the gunnel, he fell over-board : the sea was rough, and the 

 yacht had great way ; so that he was presently at a considerable distance from 

 the vessel. The skiff was immediately let down ; but the painter not being fast, 

 the rope ran an end, and the skiff went adrift. One of the seamen jumpt over- 

 board, got into the boat, brought her alongside the vessel, took in another man, 

 and then went after the youth, whom they recovered, after he had been in 

 the water more than half an hour. The young gentleman, relating the affair, 

 said, that as he could swim very little, and judging he should sink if he strove 

 against the waves, he turned on his back, and committed himself to their 

 mercy. He kept himself perfectly calm ; and observed, when a wave was likely 

 to break over him, to hold his breath, and to spurt out the water forced into 

 his mouth. His hat, which happened to be tied by a piece of string to one of 



