862 Kohlrausch and Loomis—Influence of Temperature 
TABLE 5. 
Decrease of the coeff. 
of elastic. for an incr. 
of oe of 1° as func. 
of the Rom pte of elast. at 
Temp. | Observed. Calcul. | Observ.— Cal. 
Iron. IV| 29°-9 | 0000467) 0000454, + 0:000013 
2 482 455 
Sh 32 + 27 
III} 40°3 450 457 | — 07 
43°7 416 458; — 42 
43 445 458) — 13 
66°1 459 463; — 04 
66°6 494 463| + 31 
IV 
II 
II 
I 
ItI| 66-9 459 464 
Copper.| ITI] 32-1 | 0-000566| 0-000538| + 0-000028 
Ij 32-4 528 a8i. — 10 
II 
I 
ul 
I 
Ill 
ie 
Brass. 12°2 | 0°000466) 0:000461| + 0:000005 
TT} 31:7 504 514] — 10 
I) 384 523 532) — 09 
IV| 38-7 570 533) + 37 
IIT) 42°7 514 544) — 30 
IV| 46-4 556 554) + 02 
J) 58-5 593 587) + 06 
IIT} 59°7 584 590); — 06 
II} 60°5 599 592] + 07 
If the other definition of the modulus of elasticity is em- 
ployed (as was done by Wertheim) referring to the section, and 
not, as above, to the mass of the unity of the length of the 
wire, the coeflicients of ¢ ike temperature will be slightly altered 
in accordance with the observation on page 357. If the coefti- 
cients of dilatation for 1° are assumed to be for iron =0-000012 ; 
~ copper = 0°0000175; and for brass = 0:000019, the coefii- 
ents of t become, 
for r iron 0°000483, 
for copper 0000572, 
for bra: 0°000485. 
The coefficients of roe aad terms remain sensibly un- 
changed. 
It is evident from the results of these observations that the 
mean variation of the elasticity for the three metals investigated 
ot but little from that of the temperature. For a change 
of temperature from 0° to ne the diminution is for 
Tron, ‘6 and Ae per cent, 
Copper, : : be. 
Brass, Beg ‘a - 
Oy ee 
OST en 
