iM 



MR. BEVAN ON THE MODULUS OF TORSION. 



Table (Continued). 



Species of Wood. 



Crab . . 

 Damson . 

 Deal, Christiana 

 Elder . . . 

 Elm . . . 

 Fir, Scotch . 

 Hazel . . . 

 Holly . . . 

 Horabeam . 

 Laburnum 

 Lance-wood . 

 Larch ... 

 Lime or Linden 

 Maple . . . 

 Oak, English 

 Oak, Hamburgh 

 Oak, Dantzic 

 Oak, from Bog 

 Ozier . . . 

 Pear . . . 

 Pine, St. Petersburg!! 

 Pine, St. Petersburgh 

 Pine, Memel. 

 Pine, American 

 Plane . . 

 Plum . . 

 Poplar . . 

 Satin-wood 

 Sallow . . 

 Sycamore . 

 Teak . . 

 Teak, African 

 Walnut . . 



Specific 

 gravity. 



.763 



.38 

 .755 



.83 

 .86 



LOl 

 .58 

 .675 

 .735 



Modulus of 

 Torsion. 

 Pounds. 



.693 

 .586 

 .67 



.72 



.59 

 .79 

 .333 

 1.02 



.572 



22738 

 23500 

 11220 

 22285 

 13500 

 13700 

 26325 

 20543 

 26411 

 18000 

 25245 

 18967 

 18309 

 23947 

 20000 

 12000 

 16600 

 14500 

 18700 

 18115 

 10500 

 13000 

 15000 

 14750 



17617 

 23700 

 9473 

 30000 

 18600 

 22900 

 16800 

 27300 

 19784 



Observations. 



Not quite dry. 



Not quite dry. 

 Green, or fresh cut. 



Partly cross-grained. 



Fresh. 



Four or five years old. 



Old, and partially decayed. 



I have observed in a great number of my experiments, that the modulus of 

 torsion bears a near relation to the weight of the wood when dry, whatever 

 may be the species ; and that for practical purposes we may obtain the deflec- 

 tion (S) from the specific^ gravity (s). Thus 



'Iw 



SOOOOtJ* s 



= i. 



