The Mapping of the Earth. 569 
to complete the accurate trigonometrical surveying and topographical 
mapping of the earth’s land-surface, including the parts of the 
Polar regions that may possibly be land—that is, the 60,000,000 
square miles which we have taken for this total area; but this will 
certainly not be the case, since the rate at which such surveys have 
been carried out has been greatly accelerated during recent years, 
owing to the rapidly increasing demands for accurate topographical 
maps, improvements in methods, and other causes, so that it will 
possibly not be half this time before all the parts of the earth’s 
surface that are likely to be of any use to man as settlements, or 
capable of his development, are properly surveyed and mapped. 
There are, of course, regions, such as those near the Poles and in the 
arid deserts, that are never likely to be accurately triangulated and 
mapped to any extent, and it would be mere waste of time and 
money to attempt anything of the kind... . 
Many and varied have been the influences that have led to the 
surveying and mapping that have already been accomplished, and it 
would be interesting if we had time to analyse them. Among the 
preliminary surveys, I think it would be found that military 
operations would hold an important place. Many an unexplored 
region has been mapped for the first time as the result of frontier 
expeditions, such as those of the frontier regions of India and parts 
of Central and South Africa, while the need of a more exact 
acquaintance with the topographical features for military require- 
ments have frequently led to more exact trigonometrical surveys. 
Our own Ordnance Survey is indeed an example of this, for in the 
first place it resulted from the military operations in Scotland in the 
latter part of the eighteenth century. 
Among other causes that have resulted in surveying and 
mapping might be mentioned the delimitation of boundaries, com- 
mercial or industrial undertakings, such as gold-mining and land- 
development, projects for new railways, all of which have at times 
been fruitful in good cartographical results. Nor must we forget 
Christian missions. The better-trained missionary has always 
recognized the importance of some sort of a survey of the remote 
field of his operations, and the route to it, if for no other reason, 
with a view to the good of his fellow-workers and those who come 
after him; and in the earlier days especially perhaps most of all 
pioneer mapping was done by the self-sacrificing service of the 
missionary. We have only to think of such men as Moffat, Living- 
stone, Arnot, Grenfell, and others of the same sort to be reminded of 
the debt due to the missionary from all interested in geographical 
mapping... . 
The future surveyor will be in a much better position than his 
predecessors, not only on account of the improvements in instruments 
and apparatus for his work, but because, in many parts, a good 
beginning has been made with the triangulation to which the new 
surveys can be adjusted. In Asia a considerable amount of new work 
of this kind has been done over the frontier of India in recent years 
by the Survey of India, among the more important of which is the 
connecting of the Indian triangulation with that of Russia by way 
