1910. | Anniversary Address by Sir A. Getkie. 269 
During the third period of his work, 1892—1903, Prof. Bower’s papers, 
including an important series on the spore-producing members, have resource- 
fully maintained the antithetic doctrine, and have afforded a striking instance 
of the advantage of a well-considered working hypothesis as a guide to investi- 
gation. The career of morphological research here outlined has been recently 
crowned by the publication (1908) of a book on “The Origin of a Land 
Flora,” which is one of the “ most important contributions to the advance- 
ment of Natural Knowledge, published originally in His Majesty’s dominions,” 
within the period prescribed in respect of the award of Royal Medals. 
The other Royal Medal has been adjudged to Prof. John Joly, who is 
eminent in two branches of science, geology and physics. This combination 
of studies has proved to be reciprocally fruitful to both departments. It was. 
from his mineralogical interests that he was led to devise the steam calori- 
meter, which has enriched physics with an apparatus of high refinement. The 
use of this method was extended by him to the direct determination of the 
specific heats of gases at constant volume, a measurement dealing with minute 
quantities of heat under circumstances quite beyond the capabilities of the 
usual forms of calorimeter. Among many contributions to standard physical 
data, which are accepted and in use, may be instanced his determination of 
the density of saturation of steam. His meldometer, primarily intended for 
determining the melting points of mineralogical and geological specimens, 
has been the means of providing data for use in thermometry. He has. 
devised and applied a method of determining the change of volume of rocks 
and other substances on fusion, which is a datum of primary importance for 
cosmical theories. He has carried out a refined research, with negative 
results, on the possibility of minute change of mass (as distinguished 
from weight) accompanying chemical combination. His recent extended 
investigations of the occurrence of radioactive substances in materials. 
from various strata have been utilised for fundamental geological dis- 
cussions. Of other useful inventions which he has introduced, one of 
the best known is the translucent block photometer. 
Prof. Joly has made important contributions to the subject of colour 
photography, and devised some years ago a three-colour system in which all 
three colours are present on the same plate in the form of fine parallel lines 
or small dots. 
He has also contributed substantially to the theory of biological processes, 
such as the ascent of sap in vegetation. Reference may likewise be made to 
his suggestive memoir on the Age of the Earth based upon a discussion of 
the chemical constitution of the Ocean. 
