The Geographical Journal (Journal of the Royal Geographical Society): Volume X, No. 6 [‎116r] (84/186)

THE TOPOGRAPHICAL WORK OF THE GEOLOGICAL SURVEY OF CANADA.
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their hydrographic bureaus for the study of irrigation; Germany, Austria, and
Hungary have their hydrographic bureaus for studying river-floods. But if much
is already done as to investigation for practical purposes, more still remains to do in
order to develop potamology to a well-founded branch of physical geography.
THE TOPOGRAPHICAL WORK OF THE GEOLOGICAL SURVEY
OF CANADA.*
By J. BURR TYRRELL. M.A.. B.Sc., F.G.S.
Most of the difficulties encountered in making a geological survey of Canada have
arisen from the want of good topographical maps. In the absence of an ordnance
or similar survey, the Geological Survey, as the only organization charged with the
mapping of the Dominion as a whole, has had to undertake, concurrently with
the geological work, extensive topographical surveys from its very inception to
the present time. The surveys in Canada that are available for topographical maps
are, in general, Dominion Lands and Crown Lands surveys. The former is based on
an accurate system, but applies only to Manitoba, the North-West Territories, and
a narrow belt along the Canadian Paciflc railway in British Columbia; and its
operations have, thus far, been confined to a portion of the railway belt, and to the
country south of the North Saskachewan and lying between the Rocky mountains
on the west and the boundary between Ontario and Manitoba on the east.
The Crown Lands Departments of Ontario and Quebec have made cadastral
surveys in the southern portions of their respective provinces from time to time, to
meet the requirements of advancing settlements. As these townships are surveyed
independently, and sometimes not very correctly, extensive surveys have to be
made to check and correct them, and to add roads, railways, etc., that have been
constructed since they were surveyed. The other provinces have made no surveys
available for mapping purposes except in isolated areas.
Again, the Geological Survey, as the pioneer preceding the lumberman, the
miner, and the settler, has frequently to make explorations and surveys in districts
that are subsequently cadastrally surveyed by the Dominion Lands or Crown Lands,
The maps issued by the survey may conveniently be divided into—
(1) Preliminary maps on scales varying from 8 to 25 miles to 1 inch. These
are usually the results of reconnaissance and exploratory surveys in the great areas
of Northern Canada.
(2) Detailed maps on scales of 1, 4, and 8 miles to 1 inch. These maps are
published in sheets of standard size and on standard scales, and their publication
must obviously proceed more slowly than those of the first class.
As the topographical work of the survey is for mapping purposes only, it is-
necessary to strive after no greater accuracy and no greater detail than is required
for the scale of the map in view. The methods of survey used are therefore of an
elastic nature, varying with varying circumstances, and are usually a combination
of two or more of the following:—
(1) Transit or compass and chain surveys or triangulation A surveying technique in which the position of a network of points is determined by creating a series of triangles between them and measuring at least two of the internal angles and one side length. .
(2) Micrometer or, if on roads, odometer surveys.
(3) Paced surveys.
* Paper read before Section E (Geography) at the Toronto meeting of the British-
Association, August, 1897.