4.90 REPORT—1905. 
Secrion G.—ENGINEERING. 
PRESIDENT OF THE SEcTION—Colonel Sir Corin Scorr Moncrierr, 
G.C.8.1., K.C.M.G., R.E. 
The President delivered the following Address at Johannesburg on Tuesday, 
August 29 :— 
Science has been defined as the medium through which the knowledge of the 
few can be rendered available to the many; and among the first to avail himself 
' of this knowledge is the engineer. He has created a young science, the offspring, 
as it were, of the older sciences, for without them engineering could have no 
existence. 
The astronomer, gazing through long ages at the heavens and laying down the 
courses of the stars, has taught the engineer where to find his place on the earth’s 
surface. 
The geologist has taught him where he may find the stones and the minerals 
which he requires, where he may count on firm rock beneath the soil to build on, 
where he may be certain he will find none. 
The chemist has taught him of the subtle gases and fluids which fill all space, 
and has shown him how they may be transformed and transfused for his purposes. 
The botanist has taught him the properties of all trees and plants, ‘from the 
cedar tree that is in Lebanon even unto the hyssop that springeth out of the 
wall.’ 
Ard all this knowledge would be as nothing to the engineer had he not 
reaped the fruits of that most severe of all pure and noble sciences—the science 
of numbers and dimensions, of lines and curves and spaces, of surfaces and solids 
—the science of mathematics. 
Were I to attempt in the course of a single address to touch on all the many 
branches of engineering, I could do no more than repeat a number of platitudes, 
which you know at least as well as I do. You would probably have fallen asleep 
before I was half finished, and it would be the best thing you could do. I think, then, 
that it will be better to select one branch, a branch on which comparatively little 
has been written, which has, I understand, a special interest for South Africa, and 
which has occupied the best years of my life in India, Southern Europe, Central 
Asia, and Egypt—I mean the science of irrigation. My subject is water—living, 
life-giving water. It can surely never be a dry subject ; but we all know that with 
the best text to preach on the preacher may be as dry as dust. 
Irrigation: What it Means. 
Irrigation may be defined as the artificial application of water to land for 
the purposes of agriculture. It is, then, precisely the opposite of drainage, which is 
the artificial removal of water from lands which have become saturated, to the 
detriment of agriculture. A drain, like a river, goes on increasing as affluents 
join it. An irrigation channel goes on diminishing as water is drawn off it, 
