THE MEASUREMENT OF STRESS BY THERMAL METHODS. 237 
TasieE III. 
Steel specimen.—Internal diameter =0°406 inches. 
External diameter =0°482 inches. 
Area =0°'067 square inches. 
Stress in Ibs, 
per sq. inch 1,493 14,926 29,852 35,824 37,157 
2,400 2,500 
Toad, lbs. m0 1,000 2A | din, overstrain | }-in. overstrain 
Temp. Fahr, Read& =A Reads, A Reads. A Read®. A Read&, A 
70 0 0 0 0 0 
-12 -13 -11 -—12 -12 
75 12 13 11 12 12 
—14 -13 -12 -12 — 12 
80 26 26 23 24 24 
—12 -12 -13 -11 -10 
85 38 38 36 35 34 
-12 -—12 -13 - 13 —12 
90 50 50 49 48 46 
-12 -13 -12 —13 -1ll 
95 62 63 61 61 57 
-13 -12 -11 -12 —12 
100 75 75 72 73 69 
-11 -11 -12 —12 -13 
105 86 86 84 85 82 
-13 -12 -13 -12 -11 
110 99 98 97 97 93 
-—14 -13 —13 —12 -13 
115 113 111 110 109 106 
-13 -ll —12 -—13 -13 
120 126 122 122 122 119 
-12 —12 -13 -11 -—13 
125 138 134 135 133 132 
-13 -12 -13 —12 —Il1 
130 151 146 148 145 143 
-—13 -11 -12 -13 -12 
135 164 LEY) 160 158 155 
-12 -13 =— 12 —14 -—16 
140 176 170 172 172 171 
-13 —12 =13 -l11 -11 
145 189 182 185 183 182 
-13 -13 | —14 -13 —12 
150 202 195 199 196 194 
—14 -—1l -12 —12 —14 
155 216 206 211 208 208 
—12 -—12 —13 —12 -— 138 
160 228 218 224 220 221 
-13 -—12 -14 —15 -13 
165 241 230 238 235 234 
-13 — 13 -12 -15 -13 
170 254 243 250 250 247 
—16 —13 —15 —14 
175 —_ 259 263 265 260 
—13 —15 
180 = ; 276 280 -- 
TRANS. ROY. SOC. EDIN., VOL. XLI. PART II. (NO. 9). 36 
