94 SECTIONAL ADDRESSES 
they be lineal descendents or merely neighbours. Even the layman knows 
how puzzling it is—and often how unnecessary—to mark out frontiers 
between adjoining sciences. There will often, probably always, be an 
undefined borderland, into which both neighbours stray on their legitimate 
rounds, though working generally, unlike trespassers across political 
frontiers, in mutual helpfulness when they meet. Such a borderland 
must of necessity surround geography ; and in some directions indeed 
it seems to be more extensive than the science, when thoroughly estab- 
lished, will require. All that need be postulated at present is that, in 
order to be a competent geographer, it is not imperative that you should 
first be a skilled astronomer, geologist, and historian. Your value as a 
teacher and as a student will be enhanced by some acquaintance with 
these and the other bordering sciences; but to the ordinary man or 
woman with no such equipment, geography will still offer a vast and 
self-contained field of intelligent interest. It is from the standpoint of 
this ordinary man or woman that I would invite you to survey with me 
some portions of the field, to consider how they serve the purposes of a 
true science, and then to enquire how this science can be advanced (the 
word is taken from the British Association’s title) so as to enter more 
intimately into the cultural outfit of future ordinary men and women 
like ourselves. 
lp 
To many there is a particular attraction in that remote corner of the 
field where geography stands disclosed as a science, not of immutable 
but of ever-changing data, as a study not of a solid earth and everlasting 
hills, but of a surface amply responding to Lucretius’ doctrine of flux. 
We mortals of the day live, it is surmised, in an inter-glacial epoch. It 
is only a fraction of time since this green and pleasant land of England 
was buried deep under an ice-cap, such as Admiral Byrd saw with some- 
thing akin to terror, when he was flying in the Antarctic. It may be 
only another fraction of time before all that we see around us to-day 
is crushed into oblivion by another glacial visitation. How many such 
changes and catastrophes in the past will the record of geography unfold 
when we are able to read it? Meanwhile we can only guess at some of 
them ; picture after picture of an earlier world-surface passing through 
the mind, without any pretence at chronological sequence. We can 
travel, for example, from the ice-bound Britain of which we have just 
been thinking to the African Sahara, then a moist, warm expanse of open 
grass-land, abounding in flocks and herds, and peopled by men primitive 
enough, but yet with a startling artistic skill in rock drawings. Or, instead 
of wandering south from the glaciers of Central Europe, we can turn 
east to the other gigantic ice-fields, which then lay over the uplands of 
Asia and segregated, in their own home territories, to develop on their 
own separate lines, the progenitors of some of the chief racial families 
of mankind to-day. On our way we should pass that ancient central 
Asian ocean which is now representated by shrunken fragments in Lake 
Aral and the Caspian Sea. If, following the same line of thought, we 
try to cast our mind still further back, we get into a sphere of endless 
