SECTION III., 1910. [19] Trans. R. S. C. 
IL.—On the Thermal Expansion of Rock at High Temperatures. 
By N. E. WHEE ter, BS. 
(Communicated by Dr. H. T. i urnes, and read 27th September 1910.) 
At the request of Dean Frank D. Adams, F.R.S., some experiments 
were carried out during the autumn of 1909 by Dr. H. L. Bronson and 
Mr. G. St. G. Sproule to determine the relative expansion of a certain 
nickel-steel alloy, and of granite and diabase up to a comparatively high 
temperature. The apparatus then used was designed by Dr. Barnes 
and Dr. Stansfield, and the preliminary results obtained were such as to 
make a further study of the various rocks desirable. Accordingly it was 
suggested to the writer, by Dr. Barnes, that careful measurements be 
made to determine the behaviour of various rocks as regards their ex- 
pansion up to a temperature of 1000°C. 
As will appear from the following historical account, the previous 
experiments have for the most part been conducted at comparatively low 
temperatures. In fact, little work upon rocks where the temperature 
range was large, say from 20° to 1000° C., has up to this time been pub- 
lished. While it may be true that from an economic point of view the 
investigation of the thermal expansion of rock at ordinary temperatures 
is more important, yet it would seem that the thermal expansion at the 
higher temperatures and the effects thereby produced are, both econom- 
ically and geologically, of no small importance. 
The geological importance of the thermal expansion of rocks is em- 
phasized by a work published in 1886 by T. Mellard Reade, C.E., F.G.S., 
F.R.I.B.A., Past President of the Liverpool Geological Society, on 
“The Origin of Mountain Ranges.” Reade sets forth the idea of the 
“competency of expansion by heat to produce all the phenomena of 
mountain structure.” He gives a general review of the geological evi- 
dence which goes to establish the theory that mountain upheaval is 
associated with previous sedimentation over the given area,—this 
sedimentation producing in turn a rise of the isogeotherms in the earth’s 
crust, with the result that the thermal expansion of the rock causes an 
upward movement. In this way, Reade maintains, ridges at least equal- 
ling in height any known mountain systems might be formed. 
Reade’s method of determining the coefficients of expansion of 
various rocks was to measure with vernier calipers the length, and to 
determine the temperature of bars of stone about 15 inches long, both 
before and after heating them in an ordinary oven, either with or without 
a sand bath, but always on a board. Corrections were made to allow 
for the cooling of the stone after removal from the oven and for the 
