Tables 38-39. 

 ELASTIC MODULI. 



71 



TABLE 38. — Rigidity Modulus. 



If to the four consecutive faces of a cube a tangential stress is applied, opposite in direction on 

 adjacent sides, the modulus of rigidity is obtained by dividing the numerical value of the tangential 

 stress per unit area (kg. per sq. mm.) by the number representing the change of angles on the 

 non-stressed faces, measured in radians. 



Substance. 



Aluminum 



" cast .... 

 Brass 



" cast, 60 Cu+ 12 Sn 

 Bismuth, slowly cooled . 

 Bronze, cast, 86 Cu + 1 2 Sn 

 Cadmium, cast .... 

 Copper, cast 



it 

 Gold ...'.'.*.*.! 



Iron, cast 



Magnesium, cast . . . 



Nickel 



Phosphor bronze . . . 



Rigidity 

 Modulus. 



3350 

 2580 



3550 

 3715 

 3700 

 1240 

 4060 

 2450 

 4780 



4213 

 4450 

 4664 

 2850 

 3950 

 5210 

 6706 



7975 

 6940 

 8108 



7505 

 1710 

 7820 

 4359 



Refer- 



14 



5 



10 

 II 



5 

 5 

 5 

 5 



19 



5 

 14 



5 



IS 

 10 



7 

 16 



14 

 5 

 5 



II 



Substance. 



Quartz fibre . . . 

 (( t( 



Silver 



" hard-drawn . 

 Steel 



" cast . . . . 



" cast, coarse gr. 



" silver- . . . 

 Tin, cast . . . . 



Zinc 



Platinum . . . . 



Glass 



Clay rock . . . . 



Granite 



Marble 



Slate 



Rigidity 

 Modulus. 



2S88 

 2380 

 2960 

 2650 

 2566 

 2816 

 8290 



7458 

 8070 

 7872 

 1730 

 1543 

 3880 

 3820 

 6630 

 6220 



2350 

 2730 

 1770 

 1280 

 II90 

 2290 



Refer- 

 ence. 



20 

 21 



s 



10 



16 



II 



16 

 15 



5 

 II 



5 

 19 



5 



19 

 16 

 22 



23 



23 

 23 

 23 



References 1-16, see Table 48. 

 17 Gratz, Wied. Ann. 28, 18S6. 

 iS Savart, Fogg. Ann. 16, 1829. 



19 Kiewiet, Diss. Gottingen, 1886. 



20 Threlfall, Philos. Mag. (5) 30, i{ 



21 Boys, Philos. Mag. (5) 30, 1890. 



22 Thomson, Lord Kelvin. 



23 Gray and Milne. 



24 Adams-Coker, Carnegie Publ. No. 46, 



1906. 



TABLE 39. — VarlaUon of the Rigidity Modulus with the Temperature. 



n, = fi„ (i — af — fif^ — yi^), where ^ = temperature Centigrade. 



Substance. 



Brass . 



Copper . 



Iron . . 



Platinum 

 Silver . 

 Steel . 



2652 

 3200 

 3972 

 3900 

 8108 

 6940 

 6632 

 2566 

 8290 



2158 



2716 



572 

 206 



483 

 III 



187 



(3io8 



36 



19 

 12 



38 

 59 



yio" 



32 



47 

 — II 



II 

 —9 



Authority. 



Pisati, Nuovo Cimento, 5, 34, 1879. 



Kohlrausch-Loomis, Pogg. Ann. 141. 



Pisati, loc. cit. 



K and L, loc. cit. 



Pisati, loc. cit. 



K and L, loc. cit. 



Pisati, loc. cit. 



nt*z=nv> [i — o (/— 15)]; Horton, Philos. Trans. 204 A, 1905. 



Copper 

 Copper (com- 

 mercial) 

 Iron 



Steel 



4-37^ 



3.80 

 8.26 



S.45 



=.00039 



.00038 

 .00029 

 .00026 



a = .00012 

 .00031 

 .00048 

 .00148 



Tin 

 Lead 

 Cadmium 

 Quartz 



1.50^ 

 C.80 

 2.31 

 3.00 



a =.00416 

 .00164 

 .0058 



.00012 



Smithsonian Tables. 



* Modulus of rigidity in lo" dynes per sq. cm. 



