in changing the dimensions of Iron and Steel bars. 99 
C the pore or elongations observed after the first made 
circuit had been broken ; rmanent elongations or re- 
tractions phoaryed in the rod after the first circuit passed had been 
roken; E the elongations or retractions produced on making 
the second and subsequent circuits ; F the elongations or retrac- 
tions eae on breaking the second and subsequently formed 
circu 
Table of the Elongations and Retractions of the Rods. 
TABLE I. 
Elongations and Retractions in Units of the Telescope-scale. 
to oe Cc. D. E, F. 
1 1:25 ef Thr “4 6 tof T rf 
2 16 e 1:2 r* “4 @ 1°2 e 12 ¢ 
3 20 e 9r Ik eé 1-4 ef 1-4 r* 
4 2°5 e® 115r 1°35 e* 115e 115r 
5 1°65 € 6 r 1°05 e 10 e 10 7 
6 14 e “85 r “bb 9 e 9 rT 
000 | +3 & 6 6 1-4 ef 25 r 25 e 
00 25 r ‘5 e 25 e 5 rt 5 e* 
0 ‘4 rt "25 ef ‘15 r} 2 rt 2 ef 
TABLE IT. 
Elongations and Retractions in Fractions of an inch. 
A. B. C. D. E. F. 
1 |"0001375 inch|-0000825 inch|-000044 inch|-000077 inch|-000077 inch 
2 {000176 = |-000132 «= |-o00044 “ |-000132 “ |-000132 “ 
3 000220 0099 = +=|-900121 “ |-00015 “ |-000154 = 
4 0275 “ |-0001265 “ |-0001485 “ |-0001265 “ |-0001265 “ 
5 0001815“ |-000066 +“ |-0001155 “ |-000110 “ |-000110 “ 
6 Ol “ |-0000935 “ |-9000605 “ |-000099 “ |-000099 “ 
000 |-0001168 “ |-ooooste * |-o0020a4 * |-0000365 * |-0000365 
00 {0000365 « |-o000730 « |-o000365 “ |-0000730 “ |-0000730 
2 10000534 « |-o000365 « |-o000219 “ [0000292 “ |-0000292 
TABLE III. 
—______ Coefficients of Elongations and of Retractions. 
oe ft oT z. F. 
: "000002288 ef/-000001377 r |-000000732 ef|-000001281 ef/000001281 rt 
| (000002928 e |-000002196 r*|-000000732 e¢|-000002196 e |-000002196 r 
: 900003660 e |-000001647 r |000002013 e |000002562 00002562 r* 
~ 000004575 e*|-000002105 r |-000002471 e*|-0000020 00002088 r 
; 000003019 e |-000001098 r#|-000001921 e |000001830 e |-000001830 r 
. 000002562 e |-000001555 r BO00OL IRE 000001647 e [000001647 r 
< 00000194 e*|-000001451 e*|-000003400 e* “000000607 7 {000000607 e 
9 {2000006 807 r [000001212  |-000000607 e |-00000121 2 r*|-000001212 e* 
~!_luiooooar rS000n080 sf -ooooonsed rf n0nn0486 rf 00000085 
* Maximum. 
+ Minimum. 
