58 Transactio7zs of the Boyal Society of South Africa. 
frequently into a study of the minute detail of instrumental appliances, on 
which must be brought to bear all the knowledge that can be derived 
from other branches of scientific work. The geologist helps us in the 
selection of stable foundations on which the engineer may erect our large 
instruments. Chemistry and physics in our photography, our optical and 
electrical appliances are of daily application, while one of the most valued 
accessories in almost all methods of precise measurement is the spider's 
web we derive from zoology. 
Astronomy in its turn has done much in the past, and in the future 
will doubtless do more to assist the development of collateral sciences. 
Thus the geologist cannot afiord to ignore, even if he does not accept as 
conclusive, the evidence furnished by astronomy as to the nature of the 
earth's crust. Exact measurements of space and time as conducted in 
physical laboratories are for the most part conducted by methods first 
designed to suit the requirements of astronomical precision, while in the 
sun and stars chemical phenomena, which may be studied with the aid of 
the spectroscope, are taking place on a scale far surpassing anything that 
can be produced in the laboratory. 
The value of free intercourse between workers in the various branches 
of science is certainly indisputable, and I wish to close my address by 
reference to the opportunities which our Society can afford in this 
respect. 
Devotees even of applied, and still more of pure, science in a young 
country are necessarily few in number and scattered. A large proportion 
of these will in the early stages of their career have been in close associa- 
tion with one or the other great centres of scientific activity of the world, 
and to such a feeling of scientific isolation almost amounting to exile, and 
consequent lack of stimulus, is almost inevitable. Important as are our 
publications, it is even more through our monthly meetings and the pro- 
motion of personal intercourse that the Society can help in its primary 
duty of — 
The Advancement of Natural Knowledge in South Africa. 
