The following information is excerpted from Doug Barnett's Early Surveys and Settlements in Central Alberta
The DLS System first established controlling lines on which to base the township surveys. It was decided to layout the System on an astronomic basis, that is "square with the world", with north-south and east-west lines following lines of latitude and longitude on the earth's surface. Starting near Winnipeg, Dominion Land Surveyors established six meridians over a period of time. A meridian is an astronomic north-south line on the earth's surface. The Principal Meridian was followed by successive Initial Meridians (the Second, Third, Fourth, Fifth, and Sixth), each about four degrees of longitude apart. The Fourth Initial Meridian later became the Alberta - Saskatchewan boundary, and the Western Provinces were extended northward from the 49th parallel (international boundary) to the 60th parallel, a distance of about 760 miles. As meridians follow the spherical curve of the earth, they converge as they are produced northward. For example, the distance between the Fourth and Fifth Meridians along the 49th parallel is about 182 miles (293 kilometres); at the 60th parallel, the distance between the same two Initial meridians is reduced to about 139 miles (224 kilometres) due to convergence of the meridians. The Dominion Lands Survey System is therefore an astronomic system with all north-south lines laid off as true meridians, and all east-west lines established as chords to parallels of latitude.
Land between the Initial Meridians was then subdivided into townships. A township is a square tract of land about six miles (9.7 kilometres) on a side, containing thirty-six sections (Figure to left.). Townships are numbered northward, starting from township one at the 49th parallel and increasing to township 126 at the 60th parallel (the north boundary of British Columbia, Alberta, Saskatchewan, and Manitoba). For example, Lethbridge is about at township eight; Red Deer at about township thirty-eight; Athabasca about township sixty-six; Fort McMurray about township eighty-nine; and Fort Chipewyan about township one hundred and twelve. A column of townships in the north-south direction is called a range. Townships lie in ranges numbered westward from each Initial Meridian, starting with range one adjoining the west side of each such meridian. There are thirty ranges between the Fourth and Fifth meridians along the 49th parallel, but due to convergence of the meridians, this reduces to only about twenty-three ranges along the north boundary of Alberta.
Townships are laid off their prescribed width along base lines running between the Initial Meridians. A base line is a line approximating a latitude circle from which townships are projected north and south to the correction lines (to be defined later). See figure above to the right. Base lines are four townships apart. The international boundary is the first base line; the second base line lies between townships four and five; the third base line between townships eight and nine; and so on northerly in regular order. For example, the fourteenth base line (between townships fifty-two and fifty-three) runs along part of Jasper Avenue in Edmonton, and the twenty-fourth base line (between townships ninety-two and ninety-three) runs near the Syncrude plant north of Fort McMurray.
Correction lines are east-west lines, midway between base lines, on which the jogs are allowed to provide for convergence of meridians, as shown in figure above to the right. They are also four townships apart. The first correction line is between townships two and three; the second between townships six and seven; the third between townships ten and eleven, and so on northerly in regular order. For example, the twelfth correction line (between townships forty-six and forty-seven) runs through Camrose, and the twenty-third correction line (between townships ninety and ninety-one) runs just north of Fort MacKay. The north boundary of Alberta is about the thirty-second correction line. The jogs along a correction line increase in length as one proceeds westerly from an Initial Meridian. For example, on the 14th correction line running through Namao north of Edmonton, the jog at the northeast comer of range ten is about 36.23 Chains (2390.8 feet = 728.7 metres), whereas the jog at the northeast comer of range twenty-five on the same correction line is about 96.60 Chains (6375.6 feet = 1943.3 metres). On the east side of each Initial Meridian the width of the last range is narrower than a full range due to the convergence between two adjacent Initial Meridians. These fractional ranges are less than six miles in width, the width varying with its position along the Initial Meridian, as shown in the figure above to the right. Sections in a fractional township are numbered the same as though the township was a full one.
The Dominion Land Survey System therefore established a practical, accurate solution to the subdivision of vast tracts of land in Western Canada. The framework of meridians and base lines provided the basis for township subdivision in the System. While readily understood and used by early settlers and even by people today, it was highly technical and complicated to layout while keeping errors under control. This required skilled government surveyors (DLS) to accomplish. Based on lines of latitude and longitude determined by astronomic field observations it covered the largest tract of land ever surveyed in North America under a single integrated system.
Township surveys subdivided the Crown land into parcels which could be sold for settlement, development and other public purposes. The figure above (on the left) shows the structure of a typical township of the Third System of Survey (the First and Second Systems, which differed mainly in allotment and width of road allowances, were laid out in southern Manitoba and south-eastern Saskatchewan up to about 1881; after that, the remainder of the Prairie Provinces was subdivided according to the Third System of Survey). North-south road allowances run every mile apart; east-west road allowances are spaced at two mile intervals. Each township contains three blind lines (east-west section lines where no road allowance is provided - called "blind lines" because they were not measured on the earlier surveys). Distances shown on the early township plans are in Chains, and areas are shown in acres. These British (Imperial) units have been retained for most township plans even after the metric system was adopted in Canada in 1971.
Each section is one mile on a side, or 80 Chains square (approximately), containing 640 acres. A Third System township therefore measures approximately 486 Chains east-west and 483 Chains north-south. Road allowances provide public access to each quarter- section. Sections are sometimes broken down into smaller units called legal subdivisions of 40 acres each; each section contains 16 legal subdivisions as shown in figure above to the right. These smaller tracts are used for smaller divisions of land bordering on rivers and lakes, Indian reserves, settlements, and for oil and gas well spacing units.
The introduction of the Torrens land registration system in Alberta, effective January 1, 1887, was made possible by the accuracy of the original township and settlement surveys and the careful collection and preservation of survey plans. The Torrens System was devised in Australia by Sir Robert Torrens in 1858, and is one of the most efficient land titles systems in the world. A government land titles office has custody of all original land titles and documents registered against them (such as mortgages, caveats and liens), thus guaranteeing the title and protecting it from fraud and wrongful possession. The Torrens system remains in use to this day for all dealings with land ownership, leasing, and related records at the Edmonton and Calgary land titles offices in Alberta, giving citizens ready access to all important land titles information related to buying, selling, and holding property.