6o SECTIONAL ADDRESSES 



does exist in the form of concessions granted for pre-university training to 

 a University Intermediate standard in subjects such as chemistry, physics, 

 and mathematics, whereby the length or intensity of the university 

 course in those subjects is reduced. 



If, however, geology could be introduced more widely into schools (as 

 it has been in some) as part of a general course in elementary science — a 

 revival and extension of Huxley's Physiography — it could with advantage 

 be supplemented by field-excursions, and related to the activities of school 

 societies and museums. 



Assuming this general training in elementary science, with possibly an 

 introduction to our subject, we may next ask how its further study is 

 related to the advance of knowledge in other sciences. 



The Contacts of Geology. 



Geology makes contact with astronomy at an early stage in the history 

 of our planet, when the astronomer hands over the new-born earth for 

 the consideration of the geologist. We accept his assurance that its birth 

 was an extremely unusual, if not almost unique, event, in that it was 

 procreated in the mere approach of solar parents and suffered gestation 

 in a hypothetical tidal disruption. By a process of condensation and 

 sweating, its constituent matter, not differing from that of the other 

 heavenly bodies, became arranged in the concentric shells that allowed 

 life to develop on the surface, and provided there the means for its 

 maintenance. 



The earth's history has been that of a pulsating globe, its crust subject 

 both to disturbances that have originated below the surface, and to 

 modifications that have arisen from the interplay of the successive spherical 

 shells known as the lithosphere, hydrosphere, and atmosphere. This 

 interplay is the result of such manifestations of energy as the gravitative 

 action of the sun and moon and radiation from the sun ; indeed, the 

 movements of the atmosphere and the action of the tides represent for the 

 geologist the music of the spheres. When and how life arose on the earth 

 is a problem scarcely nearer solution to-day than it was at the first meeting 

 of the British Association, but it is clear that not until Man had evolved 

 as a civilised being did life play more than a minor part in influencing 

 physical environment. In the earlier, as in the later, history of our planet, 

 the problems of geology were of a physico-chemical character, serving to 

 emphasise the contact of geology with its sister sciences of chemistry and 

 physics. Our appreciation of this relationship has developed in recent 

 years with the advances in geochemistry and geophysics. From a desire 

 to further such knowledge have arisen investigations concerned with the 

 stability-relations of elements, of simple chemical compounds, and of 

 minerals generally ; with the influence of temperature and pressure on 

 the solid, liquid, and gaseous materials involved in the constitution of the 

 earth ; and with the transmission of wave-motion through these materials. 

 By these studies we have come to comprehend, at least in part, the delicacy 

 of equilibrium that exists in rock matter, whether viewed from the stand- 

 points of the constitution of the atom, of phase-rule relationships or of 

 the buoyancy (isostasy) of areas of the earth's crust as a whole. Incidentally, 



