520 TRANSACTIONS OF SECTION BE. 
It would be difficult to say anything new on the subject I propose to 
deal with, and I lay no claim to do so, still less do I wish to dogmatise 
as to the best methods. When I express opinions I shall also state the 
practice of some of the principal surveys of the world, and my hearers 
having weighed the matter can accept my opinions or not according to 
their judgment. In either case my object will have been attained if 
careful consideration is given to the points raised. 
Maps may be roughly divided into three classes :— 
(1) Geographical maps—i.e., those on very small scales. 
(2) Topographical maps. The dividing line between these and geo- 
graphical maps is not very clearly defined. For the purpose of this address 
maps between the scales of four miles to the inch and 3;4,, scale will be 
considered as topographical. 
(3) Cadastral maps—.e., maps on large scales mainly for property pur- 
oses. 
As the time at my disposal will not admit of my discussing all three 
classes of maps, and as I have on a previous occasion read a paper to this 
Association on ‘ Cadastral Surveying,’ I propose to limit my remarks to 
topographical surveys and maps, 
In most of the older countries topographical surveys have originally 
been made to meet military needs, and as a rule they are carried out under 
military supervision. In order that they may be useful in case of war 
such surveys must have been made before war breaks out. The use, however, 
of topographical maps is not limited to military purposes; on the contrary, 
they have invariably proved of great value for civil requirements. In one 
respect they are more useful for civil than for military purposes, as a state 
of war occurs rarely, and hence while the maps are only occasionally used 
in connection with war, they are constantly used in connection with civil 
administration and with public and private business of all kinds. The topo- 
graphical maps of the Ordnance Survey, prepared originally solely for mili- 
tary requirements, have proved extremely useful for civil purposes. Directly 
or indirectly all the numerous maps prepared by the trade in Great Britain 
for civil use are based on them. I believe the experience of all other coun- 
tries is similar to that of the Ordnance Survey. In most countries in which 
land is of any value, a cadastral survey for land transfer purposes is needed, 
as well as a topographical survey. In some cases indeed, the need for a pro- 
perty survey has first made itself felt ; thus in the Transvaal and in the Cape 
Colony, neither of which yet has a topographical survey, there has for many 
years been a Government Survey Department for making property surveys. 
The question arises whether there should be two separate surveys, one for 
topographical and one for cadastral maps, or whether there should be only 
one survey, the topographical maps being prepared by reducing the cadastral 
survey. Incidentally the further question arises whether, if two separate 
surveys are made, they should be under one head. 
In most countries—the Ordnance Survey of the United Kingdom being 
an exception—not only are entirely separate surveys made for these two 
classes of maps, but these surveys are generally under different departments. 
In some cases the cadastral surveys are isolated farm surveys, showing little 
detail except property boundaries. Such surveys would, of course, not 
answer as a basis for topographical maps. In other cases, however, the 
cadastral surveys show all necessary detail except ground forms, which can 
be added by a separate survey. The only cadastral survey, so far as I know, 
which shows ground forms is the Ordnance Survey, whose 6-inch maps are 
contoured. 
A difficulty in the way of utilising the cadastral survey for the 
smaller scale maps arises from the fact that a cadastral survey is, from its 
