[WHEELER] THERMAL EXPANSION OF ROCK 35 






Results of Fourth Results of Fifth Results of Sixth 
Heating. Heating. Heating. 
Tempera- Total Ex- Tempera- Total Ex- | Tempera- Total Ex- 
ture. pansion. ture. pansion. ture. pansion. 
20°C 4.638 mm. 24°C. | 4.819 mm. 30°C, 4.951 mm. 
219 4.907 238 5.101 270 5.233 
446.5 5.155 434 5.351 551 5.618 
622.5 5.497 643 5.711 903 6.140 
751 | 5.742 788 5.948 1070 6.740 
885 | 5.919 886.5 | 6.098 19 15.025 
998 | 6.191 1008 oii PE GUN NN IRAN 
1037 6.350 1040 GEA9G TIN DIX AR ER 
897.5 5.915 820 NGA May ent arena: Se 
607.5 5.387 24 A Oy RIRE ER 
297.5 Ey MOA EPA NI PERTE REP ARE RUE PRE CRE 
24 AAS RE MO d'A Riera oh yo [ace REA er 



The granite cylinder became very brittle during the heatings and 
the permanent expansion was so large that it fitted rather tightly in the 
furnace after cooling. It was broken in removing it, so that no satis- 
factory measurement of its length was obtained with the vernier calipers 
after the heatings. 
A part of the granite cylinder was given to Dr. Adams to see if 
anything could be learned concerning the nature of what took place 
during the heatings and coolings, through an attempt to make a thin 
section which could be examined microscopically. The author quotes 
his remarks concerning it as follows: 
“ After the completion of the experiment the column of rock was 
more brittle than it had formerly been, and showed a tendency along 
portions of the sharp edges to disintegrate slightly. Otherwise, how- 
ever, it seemed to be tolerably hard and compact. 
“In cutting it open, however, for the purpose of making thin sec- 
tions, the rock could be seen to be apparently firm and more or less 
compact around the outer portion of the column, while in the inner 
portion it was found to be quite pulverulent, so much so that the grains 
could be shaken out, being quite separate from one another. 
“Tt would seem that the proximity of the heated surface of the 
tube had produced some effect in the way of sintering of the grains on 
the outer surface of the column, while within the unequal expansions 
