222 REPORTS ON THE STATE OF SCIENCE.—1917, 
of some of the sections which are now slumbering and give greatly increased 
interest to others. By relating the work of all the sections to a common 
scheme these will be brought into more vital contact with one another and 
become mutually dependent in a variety of ways. All this means that new life 
will be brought into the society, and the results in a few years’ time should be 
of great scientific interest and educational value.’ * 
The work of making a survey may be conveniently divided into three 
branches ; observation and record, interpretation, and exhibition. In record- 
ing regional observations the aims should be conciseness, ease of reference, 
anl suggestiveness in arrangement, and the most concise, convenient, and 
suggestive means of making records is on a map. The basis of our records, 
therefore, will be a large series of maps. But we must not overlook 
the limitations of the map nor forsake other methods of recording data, 
and in most cases our maps will be freely supplemented by written descriptions 
and photographs, statistical tables and diagrams. But maps will form the 
foundation of the survey, and it will be necessary for this reason to set 
geographical limits to the area to be surveyed. I shall return to this question 
of defining the limits of the region when speaking of the South-Eastern Union. 
For the present suffice it to say that at Croydon we have chosen a rectilinear 
area sixteen miles long and twelve miles wide. I need not enter into our reasons 
for this choice, much less describe the area itself, my sole object being to 
demonstrate the methods we adopt. Having defined the area, we must procure 
a number of maps upon which to make the records. The 1-inch scale will 
be large enough for most general records, but not for use in the field nor for 
some special records. For field work the 6-inch maps are indispensable. The 
best way to obtain the l-inch maps is from the Ordnance Survey Depart- 
ment, which issues for educational purposes lightly printed maps, with any 
heading we may choose, at very greatly reduced prices. This privileged issue 
of maps is in abeyance during the war, but I am informed that it wiN 
be resumed when the present pressure on the department due to war work is 
over. 
(A specimen of the Croydon map, of which 500 copies were procured, and a 
number showing different features of the district in manuscript, e.g., geology, 
rainfall, population, &c., and a selection of photographs, were exhibited to 
illustrate the paper from this point onward.) 
There are many maps which can be prepared without leaving the study, from 
material already available. The mere transference of written records to maps 
is often very enlightening. At the least it helps us greatly in visualising 
them. The Ordnance maps themselves contain data for several maps (e.g., 
contours, parish-boundaries, rivers), and it is only necessary to accentuate 
each set of data by coloured inks or washes upon a separate map. In most 
cases, however, the work of compilation will need supplementing to a greater 
or less extent by field observations. Concurrently with the field-work and map- 
making a systematic hunting up of all existing records of the region under 
survey will be carried out. A classified bibliography capable of indefinite 
expansion will be prepared, and a collection made of books, pamphlets, old 
maps, and manuscripts dealing with the district. In this search we shall 
rediscover many useful items which have been buried away in back numbers of 
our societies’ publications. 
Let us next pass briefly in review from the regional standpoint the various 
sections of the survey, and in so doing endeavour to arrange them so as to 
bring out their relations to and dependence upon one another. The diagram 
will help us in this. From our point of view it would be difficult 
to over-emphasise the importance of the geology of the region. It is the 
foundation upon which all else is built. Paleontology is a subject not to be 
ignored, but except in the Pleistocene beds or as an aid to zoning it has little 
regional significance. The same is true of past geological history. It is the 
present disposition of the strata and their physical and mineralogical characters 
that determine the topography of the district and profoundly influence all life 
* Proc. Croydon Nat. Hist. and Sci. Soc. 1912, p. cxxxvii. 
