AERIAL PHOTOGRAPHY. 
use—the principles of colour photography, the production of stereo- 
scopic and mosaic photographs, enlarging and reducing, the rapid pro- 
duction (especially drying and finishing) of prints, map reading and 
plotting, and a host of other subjects indispensable to the practice of 
aerial photography. Instead of the quick uncertain impression formed 
by the observer, the camera now produces a permanent, reliable record 
that can be studied at leisure. 
The amount of useful photographic survey work that could be carried 
out, especially in Australia, must be enormous. It is recognised that the 
making of topographical maps is a specialized science, and that photo- 
mapping is only one phase of the general science of cartography, which 
requires sound tra‘ning and practice. Map making has been considered 
A “HIT” RECORDED ON THE FILM OF A GUN CAMERA. 
The crossed lines serve to indicate the accuracy of the aim. Time is shown by the 
hands down to fifths of a second. 
an engineer’s job, and good pictures will not alone produce a perfect 
map. On the other hand, when certain problems already mentioned 
have been solved, the method of aerial mapping will displace an enor- 
mous amount of the present slow, less accurate, and more costly methods 
of a large amount of map making of to-day. 
Work in Avusrrarta. 
From inquiries made at the Forestry and Lands Departments of the 
various States, and the Defence Department, there is a general expression 
of sympathy with aerial photographic survey work in Australia, but all 
plead a lack of funds. Most of the Departments agree that there is a 
large amount of work awaiting to be done that could be accurately and 
quickly done by aecrophotography. The greater part of the cost is the 
initial outlay. 
0.18302.—4. 481 
