Vol. 59.] ANNIVERSARY ADDRESS OP THE PRESIDENT. lxxiii 



of the earth as an individual ; in other words, that it is a ' Geonomy ' 

 as contrasted with an ' Astronomy.' But while this description is 

 justifiable in principle, it is open to the natural objection that it 

 shares this earth-knowledge with many other sciences, especially 

 with the science of Geography. Perhaps the shortest definition 

 that has been made of our science, and one equally acceptable to 

 its students and to those who view it from the outside, is that 

 Geology is the 'science of the structure of the earth.' It is in 

 and around that earth-structure that all geological ideas centre. 

 In workiDg out the solutions of the problems presented by that 

 structure, Geology not only finds her own special and peculiar 

 mission, but extends a hand to all her sister-sciences. 



In studying the solid elements of that structure, Geology shades 

 through the science of Mineralogy into that of Chemistry. In the 

 study of the changes which the parts of that structure have undergone 

 and are now undergoing it shades through the science of Meteorology 

 into that of Physics. In the study of the successive surfaces of that 

 structure it grades into the science of Geography. In the study of 

 the stony relics of the vanished beings that once dwelt upon those 

 surfaces it joins hands with the sciences of Zoology and Botany. 

 In studying the phenomena presented by the sequence and inter- 

 relations of the rock-formations which go to the building up of that 

 structure, it finds the means of reading the past history of the earth 

 and its living inhabitants — a glory reserved for Geology alone. 



It was not until geologists discovered that the solid earth-crust 

 had a structure which was made up of definite parts or 4 formations ' 

 capable of individual recognition and description, each showing a 

 special distribution in space and in time, and each marked by 

 characteristic features capable of being compared, contrasted, and 

 reasoned about, that the science of Geology attained individuality 

 and became worthy of its name. It was this discovery — inaugurated 

 by Lehmann and Guettard about the middle of the 18th century, 

 made famous by Werner and his contemporaries towards its close, 

 and established beyond all dispute by William Smith at the dawn 

 of the next — that gave Geology a claim to be regarded as one of the 

 concrete sciences, and placed in her hands the weapons with which 

 she has fought her way onwards irresistibly to the conquest of her 

 kingdom. 



Since the days of William Smith, the careful investigation and 

 mapping out of these geological formations, igneous as well as 

 aqueous, has spread outward from the original centres of investi- 



