242 A DISCOURSE 



BOOK III. oaken billet, with an arching grain, about three quarters of an inch 

 square, and two feet long, broken with seventy-five pounds. 



June 29, 1664. 



There were made several experiments more of breaking wood : first, a 

 piece of Fir, half an inch diameter, and three inches long, at which dis- 

 tance the weight hung, broke in the plane of the gi'ain horizontally, with 

 sixty-six pounds and three-quarters, whereof fifteen pounds troy ; verti- 

 cally, with two pounds more. Also Fir of one quarter of an inch dia- 

 meter, and an inch and a half long, broke vertically with twenty pounds, 

 and horizontally with nineteen pounds. Elm of half an inch diameter, 

 and three inches long, broke horizontally with forty-seven pounds ; ver- 

 tically with twenty-three pounds. Elm a quarter of an inch diameter, 

 and an inch and a half long, broke horizontally with twelve pounds ; 

 vertically with twelve pounds, which is note-worthy. 



July 6, 1664. 



The experiment of breaking woods prosecuted : a piece of Oak of half 

 an inch diameter, and three inches long, at which distance the weight 

 hung, broke horizontally with forty-eight pounds ; vertically, with forty 

 pounds. Ash of half an inch diameter, and three inches long, horizon- 

 tally with seventy-seven pounds ; vertically, with seventy-five pounds. 

 Ash of half an inch diameter, and an inch and a half long, horizontally 



with nineteen pounds ; vertically, with ten pounds. Thus far the 



register. 



In the mean time I learn, that in the mines of Mendip, pieces of tim- 

 ber, of but the thickness of a man's arm, will support ten ton of earth ; 

 and that some of it has lain two hundred years, which is yet as firm as 

 ever, growing tough and black ; and being exposed two or three days 

 to the wind and sun, scarce yields to the axe. 



Here might come in the Problems of Cardinal Cusanus, in lib. iv. 

 Idiotse dial. 4to, concerning the different velocity of the ascent of great • 

 pieces of timber, before the smaller, submerged in water, as also of the 



