THE MEASUREMENT OF STRESS BY THERMAL METHODS. 249 
TABLE X. 
Thermopile on top Thermopile 1°72 Thermopile 1°81” | Thermopile 4” below 
of Beam. 4” above above centre. k= Thermopile +3,” below centre. k= centre. k= 0054, 
centre. k= -0044,5000} -0046, 4950 lbs. in below centre. 0044, 5000 lbs. in 5080 lbs. in 60 
Time, lbs. in 60 seconds. 60 seconds. 60 seconds. seconds. 
seconds. 
Galv'. Corr. Galvr. Corr. Galv?. Corr. Galv". Corr. Galv?. Corr. 
Readé. do. Reads. do. Readé. do. Reads. do. Readé, do. 
0 0 0 0) 0 (0) 0 0 0) 0) 0 
10 1-30 1:53 65 “66 0 — *85 — ‘87 | —1°5 — 1°54 
20 2°50 2°61 ie 1:83 — 03 | — 3:5 — 3°70 
| 
30 3°55 3°78 2°38 2°54 — 07 — 2°15 — 2:3 — 58 — 6:27 
40 4-90 5°33 2°75 3°0 | — 10 — 2°50 —2-72 | —6°5 — 7:20 
50 5°80 6°43 3°00 3°35 -— 12 — 2°75 -3°05 | -71 — 8:06 
60 7:00 7°92 3°15 3°59 —'14 —~ 3:10 —3°51 -77 — 8:95 
(a 7°60 8°85 3°08 3°61 —14 — 3°30 — 3°84 | -7:7 — 9:10 
90 7°40 8°87 2°90 3°50 —'14 — 3°25 — 3°89 | -7:1 — 88 
105 ae ade ase oe Bae — 3:00 - 3°69 
SEA BInEN Sell: 
Distance of pil < nee xt 
from centre ne of Load, pounds. specced esate cece a 
beam in inches, ; é 
4:00 5000 8:87 8:87 
Lei, 4950 3°61 3°63 
— 063 5000 - 14 - 14 
-— 1°81 5000 — 3°89 — 3°89 
— 4:00 5080 — 9:10 — 9:09 
results obtained were confirmed for the same loading by other tests. In some experi- 
ments on the variation of stress in cement beams two months old with steel reinforcing, 
the thermal method did not give satisfactory results, and apparently the combination 
does not appear to behave like a true elastic solid. On the other hand, specimens of 
cement of considerable age behave exactly like iron and steel. 
TRANS. ROY. SOC. EDIN., VOL. XLI. PART II. (NO. 9). 38 
