CORRESPONDING SOCIETIES. 223 
9. InctrreNt Evonurion. 
—_—_— 
7. Historic Recorp. 8. Socran Evonurion. 
(Descriptive). (Interpretative). 
= Oe mat = 
= 
6. Preutstoric Man. 
5. Animau Lirr. 
4. VEGETATION. 
—— 
(Edaphiec Factors). (Climatic Factors). 
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3. HyproGrRAPHY AND OROGRAPHY. 
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1. GroLoay. — - - 2. MrTEoROLOGY. 
upon the surface, from the types of vegetation to the occupations and habits 
and even the ideals of the human inhabitants. 
In geology a century of survey-work has been accomplished, and we have 
the Geological Survey maps and memoirs and much valuable amateur work to 
start with We may commence by copying on two of the maps the Drift and 
solid geology from the official maps. Where only the old inch maps are 
available it will be found impossible satisfactorily to transfer the geology to 
the new editions of Ordnance maps without some field observations. Many 
districts are more fortunate in having the new series of inch geological maps, 
while some parts have been surveyed on the 6-inch scale, and the manuscript 
maps are available for reference at Jermyn Street. 
The geological map is one of those which, like the contour and other leading 
maps, should be prepared in outline as a transparency for the purpose of 
placing over other maps for comparison. In this way many interesting points 
will be brought out. A geological model and vertical sections should also be 
prepared. 
Although so much has been done in geology, there is still plenty of scope 
for the local worker. Several lines of investigation open to him were mentioned 
by Professor Lebour in his address last year. 
Next in importance to geology is meteorology or climate—that is, the rain- 
fall, temperature, sunshine, wind, &c. The charting of meteorological records 
will add greatly to their value, and other branches of the survey will make 
good use of them. The Croydon Society has for many years made and published 
daily rainfall observations for about 100 stations under the direction of Mr. F. 
Campbell-Bayard, and in transferring some of these to maps we were fortunate 
in obtaining the help of Dr. Hugh Robert Mill, who very kindly had three of 
our maps prepared for us from his British Rainfall Organisation charts—namely, 
the average annual rainfall, and a very wet and a very dry year (1903 and 
1898). One of our members is engaged in working out a further series of 
rainfall maps. 
Meteorology competes with geology as an influence upon life, and the two 
sets of phenomena act and react upon one another. The rainfall playing upon 
the geological strata determines the hydrography of the region—that is, the 
surface and underground drainage, which, with the other atmospheric agents 
of erosion, gives us the orography or contour. z 
These three branches together form the physical environment, and directly 
dependent upon them all is the vegetation or plant-ecology. The geology and 
the hydrography on the one hand give us the edaphic ecological factors, while 
