546 Intelligence and Miscellaneous Articles, 



Consequently the quantity of heat employed in the dilatation of 

 the iron is to the total quantity absorbed as 4*81 to 49140, or as 0-98 

 to 10000. 



If we have merely to determine this ratio, the knowledge of which 

 is sufficient for the solution of various questions of theoretical physics, 

 it is not necessary to have more ample data respecting the coefficient 

 of extensibility a, because this vanishes, being a factor common to 

 both the numerator and denominator of that ratio. 



We have found 49140 = 42000^5^ and 4-81 = 100 X 1000 a, 



/3 

 whence 4-81 ^ \ ^ 100000 a/3 /3 



49140 10000 42000 c"5a 0-42 a/ 

 and, finally, for the expression of the quantity of heat transformed 

 into work, ^_ 10000 i8 



0-42^5' 



The calculation made for the particular case of iron was performed 

 in the same manner for a few other bodies. The results are recorded 

 in the last column of the following Table. The numbers have suffi- 

 cient accuracy only for ordinary temperatures. 



Iron 0-0000481 



Copper 0-0000951 



Silver 0-0001401 



Gold 0-0001791 



Platinum 0-0000628 



Lead 0-0005634 



Glass 0-0001451 



Water at 16° ., 0-0045854 



The numbers under X give the quantity of heat become latent, 

 expressed in ten-thousandths of the total heat absorbed. This por- 

 tion is only a very small aliquot part of the total heat absorbed — and 

 that not only for solid bodies, but also for water. We can thus ex- 

 plain to ourselves why all endeavours to raise the temperature of a 

 solid body by compression have hitherto been vain. We also under- 

 stand why the latent heat of extension exerts so little influence on the 

 specific heat of the atoms of solid bodies, — Bibliotheque Universelle, 

 Archives des Sciences Phys. et Nat. vol. xliv. pp. 341-344. 



/S. 



0. 



s. 



X. 



0-0000350 



7 '7 ^7 



0-1098 



0-980 



0-0000515 



8-936 



0-0949 



1-446 



0-0000573 



10-301 



00577 



2-378 



0-0000466 



18-035 



0-0324 



1-899 



0-0000265 



21-166 



0-0324 



0-920 



0-0000854 



11-165 



0-0314 



5-800 



0-0000262 



2-446 



0-1770 



1-441 



0-0001600 



0-999 



1-0000 



3-810 



EXPERIMENTS OX COLLISION WITH BALLS OF DIFFERENT METALS. 

 BY H. SCHXEEBELI*. 



In a previous communication on the collision of elastic bodies f I 

 have investigated the conditions of collision in one and the same 

 substance placed in different conditions. The substance employed 

 was steel as hard as glass, which is elastic to the highest degree. I 

 determined qualitatively in \\hat proportion the duration of the impact 

 depended on the mass, the length, and the height of fall of the striking 

 body. 



* Pogg. Ann. vol. cxlv. p. 328. t See Phil. Mag., Dec. 1872, p. 4/6. 



