3.—REPORT OF THE COMMITTEE 
ON 
THE PHOTOGRAPHIC WORK OF GEHOLOGICAL 
SURVEYS. 
MEMBERS: 
Mr. P. BARACCHI, F.R.A.S.; Professor T. W. E. DAvip, B.A.; Mr. 
T. FOURBER, F.R.A.S., L.S.; Sir JAMES HEcTOoR, K.C.M.G., M.D. 
tf i.e.; Professor R. TATE, F.G.S., F-L.5.;\ Mr. J. H. HARVEY, 
A.R.V.I.A. (Secretary). 
THis committee, which was appointed at the meeting held at 
Hobart in January, 1892, presented a progress report at the 
meeting, held in Adelaide in 1893; it was reappointed at that 
meeting, a slight alteration having been made in its constitution, 
but it was found impracticable to bring up a further report in 
1895, and at the Brisbane meeting in that year the committee 
was not reappointed. 
At the meeting held in Sydney in January, 1898, it was re- 
constituted, three of the original members (Sir J. Hector, 
Professor R. Tate, and the secretary) being still upon it. 
Since the last meeting the subject has received much atten- 
tion, and as the treatment of purely geological photography 
was fully dealt with in the report presented at the Adelaide 
meeting, the subject of topographical photography alone will 
be given consideration in this report, as was foreshadowed in 
the opening remarks of the 1893 report. 
It is not intended to give an exposition of the theory, or a 
full account of the practical means and methods employed either 
in the field or in office work for the execution of photographic 
surveys. Such an undertaking would now be superfluous, in 
view of the complete treatises upon the subject published. by 
Laussedat, in France; Capt. E. Deville, in Canada; Paganini, 
in Italy; and Reed, in America, besides other contributions to 
societies’ transactions, periodicals, &c., but it is considered that 
it will be sufficient to mention some points in connection with 
what has been done lately in Italy and Canada, the two countries 
which are at present probably the most conspicuous exponents 
of activity in the application of photography to surveying. In 
Italy this work has been carried out since 1878 by the Royal 
Geographical Military Institute at the instigation of General 
Ferrero. r 
The successful completion of topographic maps to a scale of 
1/25,000 with hypsometric contour lines at every 10 metres, 
M 
