Cartography is the art, science and technology of making maps, plans, charts and globes representing Earth or any celestial body at any scale. Cartographic documents have been used as vehicles of communication by different cultures for many millennia; the earliest map to survive, drawn about 2300 BC on a clay tablet, was found in the Middle East. Centuries before Christ, Greek philosophers and mathematicians such as Pythagoras and Aristotle advanced the concept that Earth was a sphere, and Eratosthenes (c 276-196 BC) made a reasonable calculation of Earth's circumference.

In the 2nd century AD Claudius Ptolemy compiled and systematized the geographical knowledge of the day and encouraged the scientific study of geography. He suggested, for example, that maps be drawn strictly to scale (at that time not a common practice), that general world maps should be supplemented with a series of regional maps drawn at appropriate scales, and that maps should be drawn with co-ordinates.

Ptolemy's works were ignored until early in the 15th century, when an avid interest in the classical period had been revived by the Renaissance. His writings, translated from the Byzantine Greek, were copied in manuscript and later published. In a 1507-08 edition of his Geographia, a map showing a portion of eastern Canada appeared, and during the next century the Ptolemaic atlases became a major instrument of the diffusion of geographical knowledge of Canada.

In the following centuries the mapping of Canada evolved with the advance of cartographic techniques around the world and with continued exploration along the coasts and into the heart of the country. The development of instruments and techniques also changed the nature of the data gathered and the maps produced.

The maps of the 16th century were rough and often conjectural; maps of the French period became more accurate in the better-known areas; and after 1800, with the widespread use of the sextant and advanced astronomical techniques for determining longitude (for example, using the marine chronometer), the major gaps in the map of Canada were filled. The 20th century has seen great refinement of mapping skills in Canada.

EDWARD H. DAHL

Indigenous Mapmaking

Mapmaking was a widespread and well-developed art among Canada's Indigenous people, although this fact has been largely ignored in the history of cartography. Most common were navigational maps, because the more nomadic hunting and gathering bands depended upon effective navigation over great expanses of wilderness. Maps were also drawn to facilitate trade and warfare over long distances. Military maps were used especially by the equestrian plains Indigenous people, whose war parties sometimes ventured into unfamiliar regions of the grasslands.

Indigenous navigational maps were usually drawn on the ground or in the snow. Sketched from memory, they were accompanied by verbal descriptions of the country in question. They were thus ephemeral and, in contrast to the European use of maps, required the successful traveller to rely entirely upon memory, a task for which was trained for from childhood.

When a map was committed to media which affected its size, such as skins or bark, no attempt was made to fill in the entire space. Instead, detail was elaborated only where necessary. Lakes, rivers and shorelines were accurately portrayed on most Indigenous maps, and in this respect they differ little from modern survey maps. Scale, however, was often measured by the day's journey, and hence varied according to factors affecting travel time. Scale was also varied to exaggerate or clarify significant features for navigation.

Although Europeans frequently found these maps overly simplified and often confusing, they were eminently suited to the overriding objective of most Indigenous cartography: to accentuate landmarks and indicate features such as rapids and portages to aid travellers.

Indigenous maps were also used as general media of communication and as repositories of cultural life and lore. Shawnadithit, for example, drew a series of maps to illustrate the history of her tribe, the Beothuk, in the years leading up to its extinction. Maps also recalled historical events such as battles, and the Ojibwa elaborated charts to record their earlier migrations and past sacred events.

Combined with pictographs, maps were used for general communication, most commonly in the form of notices of direction and of trips, and in missives that might properly be called "map letters." Just as Indigenous people in these ways communicated crucial geographical information to their fellows, so they afforded the early European explorers, traders and missionaries much of the geographical information that eventually carried them and their supporting enterprises from the Atlantic to the Pacific and into the Arctic.

D.W. MOODIE

Early Explorers' Mapping

Most 16th-century maps relating to Canada are manuscript compilations, often undated and anonymous, prepared by European cartographers rather than by explorers. Since cartographers had to work with available material, these maps are at times a perplexing mixture of new information and old, copied from unspecified sources. Any review of the sequence in which Canada was first mapped is therefore somewhat conjectural.

Until 1974 a map known as the "Vinland Map," acquired by Yale University almost a decade earlier and showing the northeast coast of North America, was thought to be the earliest cartographic representation of Canada. It is now generally believed to be a forgery.

The earliest known maps of Canada date from about 1502 to 1506. They depict the east coast of Newfoundland as that of an island in the North Atlantic. None of the land between Greenland and the Caribbean was known to Europeans. The most significant early configurations are those known as the "Cantino,""Canerio,""King-Hamy" (in Huntington Library, San Marino, California), "Oliveriana" (at Pesaro, Italy) and "Kunstmann II" charts.

The earliest of these is probably the "Cantino" chart (c 1502), which appears to have originated with the voyages of Gaspar Corte-Real (1500-01). No maps from John Cabot's voyage (1497) appear to have survived.

Some scholars have interpreted the La Cosa chart, dated 1500, as a confused copy of a Cabot map, whereas others have pointed out that it contains information available only as late as 1508. In any case, none of the geographical features of the map that some scholars have interpreted as showing the eastern coast of Canada can be identified in such a way as to achieve scholarly consensus.

The first printed maps to show parts of the New World, such as the Contarini (1506) and Ruysch (1507-08) maps, show the east coast of Newfoundland joined to Greenland as an extension of Asia. These configurations were probably based on the guess that Greenland and Newfoundland were connected (Corte-Real) and were all part of Asia (Cabot).

In 1507 a map by Waldseemüller was the first to separate the New World from Asia, a concept that gained popularity during the next decade.

During the 1520s the east and south shores of Newfoundland as well as the east shore of Nova Scotia became better known, and maps of this period portray geographical features less ambiguously than those of the previous 20 years. Better maps, such as the "Miller I" (c 1516-22), the Pedro Reinel (1516-20) and the map attributed to Diogo Ribeiro (the "Weimar" map, 1527), even hint at openings south and north of Newfoundland where later the Cabot Strait and the Strait of Belle Isle were explored by Jacques Cartier.

At least some of the features on these maps appear to be based on the exploration of João Alvares Fagundes (c 1519-26). The first maps showing the entire coastline from Florida to Newfoundland were based on the explorations of Esteban Gomez (1525) and Giovanni da Verrazzano (1524).

Although Gomez had hinted at an opening where the Bay of Fundy should be, all the maps of this period show an unbroken coastline. Later maps, such as the ones by Santa Cruz (1542), Lopo Homem (1554) and Diogo Homem (1558), drawn from data produced in the 1520s, demonstrate that Gomez actually suspected Nova Scotia to be an island, while some Portuguese more or less knew its true configuration.

After Cartier's explorations (1534-42) the entire cartography of Canada underwent revision. None of Cartier's maps have survived. Those believed to be closest to his originals are a chart by John Rotz (1542) depicting the results of Cartier's first voyage (1534), the Desceliers map of 1546 and the "Harleian" world map (c 1547). The last 2 depict Cartier's explorations to 1536. The outstanding contribution of these maps is that they add the gulf and river of St Lawrence to the shape of North America.

A second group of maps, based apparently on French and Portuguese mapping, depicts the St Lawrence along with more realistic shapes for Newfoundland and Nova Scotia. The best example of these maps is the so-called "Vallard map" (1547). Few printed maps of this period deserve consideration, but one of significance is the famous 1569 world chart by Gerardus Mercator, which introduced the map projection bearing his name.

Arctic mapping began with Martin Frobisher's first voyage (1576), although the southern tip of Greenland had appeared on maps since 1502. Frobisher's map of his bay on southeastern Baffin Island has survived but, since he did not place his explorations in the context of the rest of North America, cartographers were uncertain where to place it.

On the maps of George Best (1578) and Michael Lok (1582), Frobisher's Bay appears as a Northwest Passage across North America. Following the less ambiguous maps that emanated from John Davis' voyages (1585-87), Frobisher's "strait" was moved to the southern tip of Greenland, where it remained through much of the 17th century. Only a few cartographers made any attempt to link the northern discoveries with those on the St Lawrence and the East Coast. Probably the best attempt is a world map by Edward Wright printed in 1599.

C.E. HEIDENREICH

Mapping to 1763

Scientific mapping began with Samuel de Champlain in 1603. In 1613 he published the first modern-looking map of eastern Canada, combining in it his own explorations with those of Henry Hudson. By 1616 he had explored and mapped as far west as Georgian Bay. For other areas he used Indigenous maps and verbal accounts. His observations were made from compass and latitude readings as well as estimates of distance. Besides his 6 small-scale maps, of which that of 1632 is the most comprehensive, Champlain also produced 23 large-scale maps and picture plans of places between Cape Cod and Montréal.

From the time of Champlain's death in 1635 to the 1670s, the major explorers furnishing geographical information to European cartographers were Jesuit missionaries. By 1649 they had explored the eastern Great Lakes; the maps of Father Sanson (1650, 1656), and Fathers Bressani (1657) and Du Creux (1660) have survived in printed form. On these the Great Lakes are recognizable for the first time.

Further Jesuit mapping led to the first good map of Lake Superior and northern Lake Michigan (1672) by Fathers Allouez and Dablon; the first delineation of the Mississippi River by Father Marquette and Louis Jolliet (1673); and a series of maps of the Iroquois country in upper New York state by Father Raffeix and others.

One of the few non-Jesuit maps of the period was by the Sulpician Bréhant de Galinée, detailing his journey with François Dollier from Montréal through the lower Great Lakes to Sault Ste Marie (1670). The necessary observations used to construct all these maps were similar to those used for Champlain's. In 1632 the Jesuits began to observe and, later, to time lunar eclipses to establish longitude west of Paris or Rome.

From the 1670s to the end of the century, the mapping of Canada is primarily associated with Jolliet and Jean-Baptiste-Louis Franquelin, the latter being the more talented draftsman. He was Hydrographe du Roy at Québec 1686-97 and 1701-03, teaching hydrography and keeping the maps of New France up to date.

The manuscript maps of explorers such as La Salle, Jolliet and a number of military surveyors were incorporated in large compilations sent to France, where professional cartographers had access to them. The chief cartographers to the French court, such as Vincenzo Coronelli and Guillaume Delisle, based their printed maps in part on the information furnished by Franquelin.

The maps of Coronelli (1688-89) and Delisle (1703) best sum up the late 17th-century cartography of Canada. The Delisle map also has the distinction of being the first with a fairly modern grid of longitude based on a lunar eclipse recorded at Québec in 1685 by Jean Deshayes.

Large-scale mapping during the 17th century was understandably confined to the St Lawrence River valley. Cadastral mapping (ie, mapping of property boundaries, building locations, etc) commenced with Jean Bourdon's mapping of seigneuries (1641); Bourdon also produced an early plan of Québec (1660). The St Lawrence River was charted by Jolliet and Franquelin (1685), but much more competently by Jean Deshayes (1685-86).

Although the printed results of Deshayes's survey (1702) became the standard chart of the river, more accurate surveys were undertaken in the mid-18th century by Testu de la Richardière (1730-41), Gabriel Pellegrin (1734-55) and others. Cadastral maps also continued to be produced during the 18th century, one of the most notable being by Jean-Baptiste Decouagne in 1709. These maps and charts were all constructed by competent surveyors and military engineers using up-to-date instruments and surveying principles.

Increasingly strained relations with England made the activities of the French military engineers more important in the 18th century. The lower Great Lakes frontier was charted with some accuracy by the engineer Gaspard-Joseph Chaussegros de Léry and his son of the same name. They also prepared maps of Québec and major fortifications from Louisbourg to Detroit.

On the East Coast one of the first accurate hydrographic surveys was made by Joseph Bernard de Chabert (1750-51). In 1750 he built Canada's first observatory at Louisbourg for astronomical observation and longitude calculation.

While the settled and strategic areas of New France were being charted by trained engineers and surveyors, the interior was still being mapped by amateurs with little training and no instruments more sophisticated than a compass. The first maps of the region west of Lake Superior resulted from the La Vérendrye expeditions after 1731, while the northern interior of Québec was being mapped by the Jesuit Father Laure. These maps portray a recognizable lake and river system.

Very little 18th-century manuscript mapping found its way to printed maps until Jacques-Nicolas Bellin became chief engineer and geographer of the Dépôt des cartes, plans et journaux of the French Ministère de la Marine. In 1744 he published 28 maps in Father P.F.X. Charlevoix's combined Histoire and Journal (1744). These were the first printed maps of Canada based on new material since Delisle's of 40 years earlier.

In succeeding years Bellin regularly updated his maps. Another important cartographer, Jean-Baptiste Bourguignon D'Anville, like Bellin, had access to original material, and he produced a series of fine maps between 1746 and 1755. Both cartographers published pamphlets explaining their source material and the reliability of their maps.

Primary English mapping of Canada before 1763 was confined entirely to the Arctic and the shores of Hudson Bay. Hudson's 1612 map of the bay's east shore and the straits was quickly replaced by maps of the entire bay by Thomas James (1633) and Luke Fox. John Thornton produced a more accurate chart for the Hudson's Bay Company (1685).

The HBC did no more mapping until Arthur Dobbs criticized the company for its dismal record in exploration; beginning in 1741, expeditions resulted in a series of excellent charts by Christopher Middleton (1743), John Wigate (1746) and Henry Ellis (1748) as far north as Repulse Bay.

In 1756 the Seven Years' War interrupted mapping activities in New France. The last French map of North America, summarizing the latest geographical information available on Canada before it passed into British hands, was Bellin's "Carte de l'Amérique septentrionale" (1755). It shows that Canada had been mapped, roughly but recognizably, to about 102° W in present-day Manitoba and along the western shore of Hudson Bay to the Arctic Circle.

C.E. HEIDENREICH

Explorers' Maps after 1763

Although Québec fell in 1760, the Treaty of Paris was not signed until February 1763. During the truce the British army under General James Murray made the first detailed survey of this area, from a point above Montréal downstream to below Québec City. The "Murray Map," of which at least 5 hand-drawn copies were made, was drawn at a scale of 2000 feet to the inch (610 m to 2.54 cm or 1:24 000) and showed much information of military importance, such as the population of villages and the positions of houses, churches and mills. Two originals of this map are held in the National Map Collection, Ottawa.

Britain's vast colonial empire in North America now stretched from the High Arctic to the Gulf of Mexico. Huge areas were essentially unknown to Europeans, with only sketchily charted coasts and a largely unmapped hinterland. For the development of resources and the expansion of trade, better charts of the harbours and coastal waters and more accurate maps of the interior were required.

There were 3 excellent surveyors serving with the British forces in Canada. Samuel Holland and Joseph Desbarres were army officers; James Cook was the master of a ship in the British fleet.

The work was divided among them: Cook was commissioned to chart the island of Newfoundland and the adjacent Labrador coast; Holland, appointed surveyor general of the Northern District of North America (which included all British holdings north of the Potomac River), concentrated on the Gulf of St Lawrence, including Prince Edward and Cape Breton islands and the New England coast; and DesBarres turned his attention to Nova Scotia, which at that time included present-day New Brunswick.

Many valuable maps and charts resulted. Cook's charts were of such high quality that his reputation was assured. DesBarres's major publication was The Atlantic Neptune, a navigational atlas of the east coast of North America containing charts at various scales, coastal views, tide tables and sailing directions. He was allowed to publish the Neptune privately under his own name, although Holland and Cook had been responsible for some of its charts.

Holland's publications concentrated on landward mapping, but of course he used the data produced by the surveys of his colleagues. His map, "A General Map of the Northern British Colonies in America," drawn at 60 miles to the inch (96.6 km to 2.54 cm or 1:3 801 500), is one of the most important of this period.

Meanwhile, other surveyors were carrying out the necessary property surveys so that farmsteads could be established. This work increased greatly after Loyalists began arriving in 1783. Settlement in Nova Scotia was handicapped by the lack of a comprehensive land-granting procedure. In the Province of Quebec (which included much of present-day southern Ontario), by contrast, the settlement of the Loyalists was carried out with military efficiency.

Governor General Frederick Haldimand and Holland devised a system, comprising townships and lots, for each settler to get a measured portion of land, surveyed at minimal cost and marked on the ground. An important requirement was the preparation of a map of each township showing the layout of farm lots and the major topographic features.

A second type of 19th-century cartographic survey that equalled the township surveys in importance was the hydrographic survey of the Great Lakes carried out originally by the British Admiralty, but after 1884 by Canadian hydrographers. The work was started in 1815 by Captain William F. Owen and was turned over to Lieutenant Henry Bayfield the following year.

During the next 40 years Bayfield supervised the surveying of the Great Lakes, the St Lawrence and the Nova Scotia coast, and was personally responsible for the high quality of the charts produced.

Throughout the 19th century and into the 20th, there were hundreds of maps drawn of parts of eastern Canada that were simply compilations and redraftings of the information available from township plans and hydrographic charts. When such maps were extended to cover an area not reached by the township surveyors, the sketch maps of geologists, foresters and even fur traders were used.

The "office compiled maps" were poor substitutes for true topographic maps, but they were inexpensive to produce and they were the only large- and medium-scale mapping that Canada could afford.

"County maps" and "county atlases" were very popular. These had a semiofficial status because the basic survey data were supplied without charge to private publishers who then added a certain amount of current information. The roads and trails opened by the settlers were shown, as were stores, mills, wharves, churches and, in many cases, individual houses. The scales ranged from 40 chains to 128 chains to the inch (804.67-2574.95 m to 2.54 cm or 1:31 680 to 1:101 376) depending on the size of the county. To increase sales the publisher inscribed the name of the owner on each occupied farm lot.

Government agencies also compiled maps from existing survey data. When Holland died in 1801, Joseph Bouchette became acting surveyor general of Lower Canada and, in 1804, surveyor general. He produced 2 remarkable maps of his province, the first in 1815 at 2.66 miles to the inch (4.28 km to 2.54 cm or 1:168 530) and a revised version in 1831 at 2.8 miles to the inch (4.5 km to 2.54 cm or 1:177 400). William MacKay's map of Nova Scotia, published in 1834 at 6 miles to the inch (9.66 km to 2.54 cm or 1:380 150), is a fine example of medium-scale mapping.

The British army produced military route-marching maps and larger-scale "reconnoitering plans" from township surveys by adding details such as the strength of bridges and the billeting capacity of villages. Examples are Colonel John Oldfield's "Map of the Province of Canada" (1843), drawn at 6 miles to the inch (1:380 150), and "Map of the Principal Communications in Canada West," drawn at 2 miles to the inch (1:126 720) in 1850 under the direction of Major George Baron de Rottenburg.

During the 1850s Bayfield made another significant contribution to Canadian mapping, instituting telegraph longitude observations at a number of eastern Canadian cities. By using the commercial telegraph companies' lines for the exchange of time signals, he was able to determine very accurately the geographical position of an observatory or a public building in each of the cities. This "known position" was then used to correct the mapping of the surrounding area.

Official Surveys

Hydrographic Surveys

The British North America Act assigned responsibility for safe navigation in Canadian waters to the federal government. This initially involved the erection and maintenance of navigational aids such as lighthouses and buoys. The charting of Canadian waters started in 1883 in Georgian Bay. Canada had hitherto relied on British Admiralty charts for navigation on the East and West coasts, and on the Bayfield charts of the Great Lakes.

During the late 19th century, navigation on Georgian Bay became very important in national development: its ports were serving agricultural areas and mining and lumbering industries, and many of these ports were developing industries to supply the westward expansion of railways and the new prairie settlements. Navigation on Georgian Bay was of little interest to the US or Britain, so the Georgian Bay Survey was set up within Canada's Department of Marine and Fisheries.

In 1891 a party from Georgian Bay was sent to Vancouver to survey Burrard Inlet. This survey was the first undertaken by Canada in salt water. In 1904 the Department of Marine and Fisheries began officially charting Canadian coastal waters. The Hydrographic Survey Branch was formed, and the Great Lakes Survey amalgamated with a unit in Public Works that had been doing harbour surveys and a unit in Railways and Canals that had been working on the St Lawrence and Ottawa rivers. In 1928 it was renamed the Canadian Hydrographic Service (see Hydrography).

Canada has the longest national coastline in the world, much of it the scene of either active shipping or resource development. The towing in 1981 of a barge-mounted ore-concentration plant, 138 m long, from Sorel on the St Lawrence River to Little Cornwallis Island in the central Arctic could not have been done if good charts had not been available. The voyage of the US supertanker Manhattan, accompanied by the Canadian icebreaker John A. Macdonald, through the Northwest Passage in 1969 also illustrates the vast responsibility of the Canadian Hydrographic Service.

Modernization

Because of Canada's size, maps have always been important in the planning and execution of major development projects. The successful settlement of the Prairie West between 1872 and the 1930s was the result of good planning, police supervision, and having each farm lot surveyed and marked on the ground before the arrival of most of the homesteaders.

Surveyors employed by the Department of the Interior marked on the ground the perimeters of the 6-mile [9.7 km] square townships and then the sidelines of each of the 36 sections within the township. They also recorded the positions of major topographic features such as rivers, streams, trails and sloughs. From these notes, draftsmen in Ottawa were able to compile the sheets of Canada's first extensive map series, the Three-Mile Sectional Maps of the Canadian Prairies drawn at 3 miles to the inch (4.83 km to 2.54 cm or 1:190 080).

Series mapping provides detailed mapping at medium or large-scale, yet the individual sheets are kept to a manageable size. Because the sheet boundaries conform to a predetermined grid, a number of sheets can be joined together to provide a large map of an extensive area such as a drainage basin, a forest-protection area, a county or even a whole province.

Ideally a country should first be covered by a large-scale topographic series that displays the complete face of the land, including artificial features, relief, drainage pattern and forest cover. In the early days Canada could afford only the rather simple maps that could be drawn from the field notes sent in by surveyors whose main employment was staking farm lots, not surveying for maps.

The first sheets of the Three-Mile Series appeared in 1892. In all, 134 sheets were published, covering approximately 1.4 million km2. Each sheet covered 8 townships north to south and from 13 to 15 townships (depending on the latitude) east to west. From 1920 to 1946, 51 of these simple outline maps were converted into true topographic maps through the addition of contours and other details. The series was abandoned in 1956 in favour of the 1:250 000 series (originally drawn at 1:253 430, or 4 miles to the inch) of the National Topographic System (NTS).

Simple straight-line surveys were ideal on the flat prairies, but impractical in the Rocky Mountains. When township surveys reached the mountains in 1886, a system was developed using panoramic photographs taken from mountain peaks. A small but important series of mountain maps resulted. The maps themselves were useful, but the technique of mapping from photographs was even more useful because it was adapted to mapping from oblique aerial photographs when these became available after 1925.

The success of the Three-Mile Series encouraged the Department of the Interior to begin similar medium-scale office-compiled mapping for eastern Canada. The department's chief geographer gathered the information from the many land surveys that had been made and compiled it into maps of a standard design.

The maps were published at 2 scales (1:250 000 and 1:500 000), and were known as the Chief Geographer's Series. The first sheet was published in 1904, and by 1948, when work was stopped, 33 sheets at 1:250 000 and another 25 at 1:500 000 had been published. For many years they were the most detailed maps available for the settled parts of eastern Canada.

The original Three-Mile Series and the Chief Geographer's Series were not contoured, and because contoured maps were a military requirement, the Department of Militia and Defence started its own series of true topographic maps in 1904. These were drawn at one mile to the inch (1.6 km to 2.54 cm or 1:63 360), and were modelled on the British Ordnance Survey maps at the same scale. This design, with a few modifications to accommodate the Canadian landscape, proved so successful that it was eventually adopted for the basic topographic mapping of Canada at the 1:50 000 scale.

Since its inception in 1842, the Geological Survey of Canada had been hampered by the lack of good base maps on which to display the results of field investigations. In many cases geologists had to do their own topographic mapping. This was poor use of geologists, so in 1908 a Topographical Survey Division was formed within the GSC. It was to provide topographic maps that could be used both as bases for geological maps and as general purpose topographic maps.

In 1920 the Department of the Interior joined the military and the geologists in the separate production of topographic maps. In 1922 senior officers in the 3 agencies began to unite their efforts into a single topographic system. After study and experimentation, by 1927 what became the NTS had been developed. It was designed as a series of map scales of 1, 2, 4, 8 and 16 miles to the inch (1.6, 3.2, 6.4, 12.9 and 25.7 km to 2.54 cm). Such a system makes topographic maps available for all requirements, ranging from military and geological use at the one-mile scale to aeronautical chart use at 8 and 16 miles to the inch.

In 1950 and 1956 the basic scales were converted to their metric equivalents of 1:50 000, 1:125 000, 1:250 000, 1:500 000 and 1:1 000 000, and in 1952 a larger scale, 1:25 000, was added to the system for military and urban use. The smallest scale, 1:1 000 000, provides the basic grid that covers the whole country. This grid is quartered successively to provide the sheet boundaries of each larger scale until the largest (1:25 000) is reached. The numbering of each sheet indicates both the scale and the position of the sheet in the grid.

Today only 2 of the NTS scales are left in the system: the 1:50 000 and the 1:250 000. Over the years the 2 smallest scales (1:500 000 and 1:1 000 000) became used almost exclusively as bases for aeronautical charts. But with the arrival of long-range jet planes in the 1960s, pilots found that charts based on the NTS grid were too small for handy use in the cockpit. During the 1970s both scales were redrawn and printed on both sides of oversize paper, thus reducing the number of sheets in both series to about one-quarter of the former count.

The 1:125 000 series was dropped because it had few uses that could not be fulfilled by either the larger 1:50 000 scale or the smaller 1:250 000. The 1:25 000 scale was very expensive to keep up-to-date because it was printed in 5 colours and covered urban rural areas where the change in topography was very rapid. Also, many of the provinces started their own large-scale mapping programs in the 1970s, so in 1978 work was stopped on the federal 1:25 000 scale. The resources previously devoted to the dropped scales are now being used to keep the 2 remaining scales up-to-date.

The 1:250 000 series was completed in 1971 in 914 sheets. At the end of 1995 the 1:50 000 series covered all provinces, the Yukon, and mainland Northwest Territories. When completed it will embrace 12 922 sheets. All the remaining sheets are of areas on the Arctic Islands, but even for these the surveying, photography and basic photogrammetry have been completed. Any of them can be put into production as soon as there is an economic reason for doing so.

By virtue of having their topographic mapping well in hand, Canadians enjoy the availability of a wide range of thematic maps: geological, forestry, pipeline and power transmission, tourist, etc. Many are produced by federal agencies, but the provinces, responsible for the development of their own natural resources, have become active in producing thematic maps.

L.M. SEBERT

Mapping Since WWII

WWII can be considered a turning point in Canadian topographic mapping. Before the war topographers used plane tables and sketched out small sections of the terrain which were subsequently joined together into a map. This method was slow, not very accurate and unusable in forested areas. Aerial photographs were used, but in the whole country only one instrument plotted map detail directly from air photos.

Photogrammetry

During the war the staff of Canada's military mapping units became familiar with European photomapping equipment, and they became a postwar source of trained technicians available for the modernization of Canada's mapping agencies. The introduction of photogrammetry (the drawing of maps from aerial photographs) was only one of many technological innovations that have transformed every phase of topographic mapping in Canada.

In remote areas, large tracts of country are normally mapped in a single operation. For example, a block 100 km north to south and 300 km east to west is mapped on 32 sheets (4 rows of 8) in the NTS. Aerial photography is done with certain features predetermined: scale, direction of the flight lines (normally east to west), forward overlap of the photos (normally 60%) and the side overlap of the flight lines (normally 30%). About 850 photos are needed.

Overlap is necessary to provide areas on the photos for "tie-points" (points of ground detail selected in the overlapping areas) used to "pin" the photos of the block together. Tie-points are marked by tiny holes drilled in the emulsion on film positives of the air photos, and are measured precisely on a grid co-ordinate system provided for each photo. Each tie-point falls on 3 or more photos, allowing individual photo grids to be combined into a master system covering the whole photogrammetric block. This extension of the grid system is done by computer.

Although photogrammetric techniques have reduced the amount of field surveying required, some surveyed points must still be placed at strategic positions in the photogrammetric block. These are "control points" because they "control" the scale, the orientation, and the position of the lines and symbols on the map. There are 2 types of control points: horizontal (precisely known latitude and longitude) and vertical (precisely known elevation).

The horizontal control points must be situated around the perimeter of the photogrammetric block where, in effect, they hold the block in position. It must be remembered that all mapping that covers an appreciable area must be drawn according to the mathematical rules of the chosen map projection.

In Canadian topographic mapping this is generally the Universal Transverse Mercator (UTM) projection, which means that the latitude and longitude values of all horizontal control points must be converted to the equivalent grid co-ordinates of the UTM projection. The grid of the photogrammetric block is then adjusted in scale and orientation to fit the UTM grid. This in turn gives UTM-grid values to all the tie-points. The vertical control is set out in lines spaced across the block at right angles to the flight lines. This allows computation of tie-point elevations above sea level.

The overlapping portion of 2 adjoining aerial photographs forms a rectangle that is about half a photo wide and a photo long. A tie-point falls in each corner of this rectangle. Such rectangles are "photogrammetric models" because when viewed through a stereoscopic instrument they appear to be 3-dimensional models of the ground. They are the mapping units of a photogrammetric block.

The models are set up, one by one, in photogrammetric plotting instruments, which are adjusted to the known values of the tie-points. The map detail is then traced from the model by the operator, who moves an optical aiming mark, visible in the eyepiece of the instrument, along the roads and streams, around the lakes, etc, of the model. As the aiming mark moves, a pencil recording every move of the mark moves over a drafting table attached to the plotter. This is the process of drawing the linework of the map.

Photogrammetric plotters have made great strides in the last 10 years. In the traditional plotter the operator obtained a 3-dimensional view of the terrain by looking through the optics of the plotter at one of the overlapping air photos with one eye and the other photo with the other eye. On modern plotters (called Digital Photogrammetric Workstations, or DPWs) the left-eye-right-eye viewing is obtained electronically.

The operator looks at a TV screen while wearing a pair of glasses that are connected to the screen by an electronic signal that acts as a shutter alternating the view through the left and right lenses very rapidly. The image on the screen appears to be an ordinary aerial photograph but actually it is both of the overlapping photos alternating so rapidly that a steady image is seen. The glasses worn by the operator alternate in step with the alternating image on the screen. A brilliant 3-dimensional image is seen which is really the melding of the 2 air photos.

The "floating mark" (a dot of light) can be moved across the screen and "lowered" to the ground when an elevation is needed or a contour is to be drawn. Map detail is traced off in the normal way. The coordinates of the floating mark are recorded very precisely on a magnetic disc using the pixel grid of the photographs for reference. This information, including colour coding, is subsequently read from the discs by computer controlled drafting machines that can work around the clock.

There are, of course, still many of the older photogrammetric plotters being used but almost all purchases of new instruments are for DPWs. The many advantages of the new system include the ease with which the original lines can be drawn and adjusted electronically, and the efficiency with which the whole map can be revised when changes in the terrain, natural and unnatural, necessitate the drawing of a new edition of the map.

Doppler Positioning System

Each phase of the mapping process has its own instrumentation, almost all of which has been developed since the 1970s. The most dramatic advances have been in satellite surveying. The "space age" began in 1957 when the Russians launched their Sputnik. Within 15 years the US Navy had developed a navigation system based on the reception of radio signal from passing satellites. From these signals the latitude and longitude of a ship could be calculated with great accuracy.

The method of observation consisted of recording radio signals from satellites passing in the sky about 1000 km above Earth. The Doppler shift (the apparent change in frequency of the satellite's radio signal as it passes overhead) was noted. The rate of change of the frequency shift is a function of the ship's distance from the satellite. As the position of the satellite is known at all times by independent tracking from known positions around the world, the ship's position can be calculated to an accuracy of about 10 m. This was far too precise for navigation needs but was ideal for the horizontal control of the 1:50 000 mapping being done in Northern Canada.

Additional points can be surveyed between Doppler stations by using an Inertial Surveying System (ISS), consisting of delicate sensors which record with remarkable accuracy any movement of the ISS set. It can be mounted in a car or helicopter, and by starting from a known position (a Doppler station or an older triangulation station), it measures the vehicle's movement along a preselected route, and gives the coordinates of stopping points where accurate positions are needed. Such a traverse is checked by stopping at known positions to confirm the accuracy of readings taken along the way. Perimeter control around a photogrammetric block is very efficiently put in position by an ISS survey, which is accurate to about 1 m.

Global Positioning System

Despite its great usefulness, DPS lasted less than 20 years. It was overtaken by another American development, the Global Positioning System (GPS). This is also a satellite system in which 24 satellites have been placed in near-circular orbits about 20 000 km above Earth.

A small portable receiver on the ground receives signals from the 3 or 4 satellites that are above the horizon at any time. The distance to each of the satellites at any instant can be computed by the receiver. This is done by electronically timing the passage of the signal from satellite to receiver. With this information a computer, built into the receiver, can calculate its position. As with the DPS, the positions of the satellites are precisely known at all times by independent tracking, and hence the latitude and longitude of the receiver can be obtained.

GPS is capable of about 1 cm accuracy if about an hour is taken for observing and if another GPS receiver is recording at a known position in the area (say within 50 km). This simultaneous recording, at a known position and the required position, is needed to cancel out the small variables that must be found in high precision work. A single receiver without any back-up can produce 1-3 m accuracy, and observations can be taken on the move, as for example in continually tracking the position of a survey ship.

Needless to say, the advent of this marvellous survey system has had a profound effect on Canadian surveying for horizontal positions. Virtually all horizontal control for mapping is now placed by GPS. Triangulation is almost a thing of the past.

Vertical Control

Vertical control, which is always needed to ensure the accuracy of the heights and contours on maps, has not yet been as affected by the satellite systems as horizontal positioning. Vertical control has traditionally been placed by lines of levels. This method is more than adequate for settled areas (levels are traditionally run along roads or railways) but is slow and costly in wilderness regions.

Shortly after WWII a Canadian invention, the Air Profile Recorder (APR), provided a method for contouring small and medium-scale maps of the Canadian North. (During WWII Canadian aeronautical charts of Northern Canada were actually published without contours simply because the charts were needed for supply flights to Britain and the USSR and no method was available to provide height information.) Today an air chart without precise height information is unthinkable, and APR was the answer to this wartime problem.

It is a radar device that measures and records the vertical distance down to the ground beneath a plane flying at a known altitude. The track of the APR plane is recorded by a downward looking 35 mm camera, and the profile of the ground is continuously plotted on paper tape. In this way elevations needed for contouring Canada's northern air charts were obtained. APR has been used around the world by many countries but today has been superseded by more accurate methods.

ISS can also be used to establish elevations since it records changes in elevation as it moves along a survey line. This is a very cost effective method for placing elevations across a photogrammetric block. An ISS elevation is correct to within 0.5-1 m whereas an APR elevation is only accurate to about 5 m.

Satellite surveying is beginning to be used for establishing elevations but at present there is a problem with this method in certain parts of Canada. As has been explained, the GPS receiver measures the distance down from passing satellites, and by trilateration establishes its horizontal position. The same readings can also establish the elevation of the aerial of the receiver but the satellite measurements are down to the spheroid of Earth rather than to sea level.

The spheroid is a mathematic smooth surface that very closely fits the real Earth. But elevations on maps are the heights above sea level, and there is generally a small vertical separation between sea level and the spheroid. (Sea level is, unfortunately, not really level; it has small humps and valleys caused by the very slight but noticeable sideways pull of gravity.)

To obtain a sea level height from satellite observations, the separation between sea level and the spheroid must be known. It is quite accurately known in settled parts of Canada but in the North it may be in doubt by as much as 3 m. Geodesists are working on this problem by taking hundreds of gravity measurements, but until their work is finished satellite elevations for many Canadian regions will have an uncertainty of about 3 m.

See also Geographic Information Systems.

L.M. SEBERT

Cadastral Surveying

"Cadastre" is a technical term used in Europe for the registration of land in a given municipal area such as a city or a county. A "cadastral survey" is the measuring, marking and description of parcels of land sufficient for their correct entry into the public land register; or, conversely, the marking on the ground of parcels in accordance with a description in the register.

In the latter instance this could be either an original survey or a retracement when the position of the original boundary is not clear. Within provincial boundaries in Canada, land ownership and all fiscal matters pertaining to land are under provincial jurisdiction. The provinces set the rules and procedures for the cadastral surveys of their lands, including the licensing of surveyors. In the Yukon, the NWT and federal lands in the provinces, such as Indian reserves and national parks, the federal government has this responsibility.

An essential part of any cadastral survey is the legal description, which must give the size, shape and location of the parcel being surveyed. It may be in writing, in writing with a plan, or entirely on a registered plan. The traditional written description is by "metes and bounds": the parcel's boundary lines are described in succession by stating the direction and length of each line, and by describing the survey markers or natural features that identify the boundary lines on the ground.

A registered plan is used when a parcel is being subdivided and a number of lots are being established simultaneously. Such a plan must show the dimensions, boundary line bearings, areas and survey markers of each lot, and each lot must be numbered or otherwise identified. It can then be identified in a deed or other document by plan and lot number and the office where the plan is registered.

In many parts of Canada the original subdivision of crown land was done by township surveys, essential to orderly settlement. Different sizes of townships have been used (eg, Québec's irregularly shaped cantons and Ontario's concession townships), but all were designed to provide rectangular farm lots within a defined rural community.

The survey of a township was essentially a subdivision survey, because the plan of the township was registered and the lots (sometimes called sections) were numbered. The description of a whole lot for legal purposes is complete in the identification of the township and the lot within the township.

If only part of a lot is in question, a metes and bounds description, or some other method such as fractional parts, must be used (eg, "the north half of Lot 24, Concession II, in the Township of North Burgess"). As cities and towns extend into rural areas, it is common to find a township farm lot being subdivided into a number of city lots.

Urban Mapping

All cities and large towns must have maps for tax assessment, for the location and planning of public utilities, for traffic planning and for many other purposes. Most cities have a survey office, but towns generally have a municipal engineer. Both are responsible for the maintenance of survey records and the custody of maps, but the actual mapping is done by contract with Canada's air-survey industry.

Cities use map scales ranging from 1:500 for plans of sewage systems to 1:50 000 for tourist maps showing complete street layouts. Cities are 3-dimensional structures, and the utility mapping must show surface construction underlain by sewers which themselves may be built over power conduits, subways, service tunnels, etc. City maps must be kept up to date; many disastrous delays in municipal works have been caused by unexpected encounters with vital utility lines. Fortunately, most Canadian cities can take pride in the completeness of their maps and survey records.

Boundary Surveys

In the "township provinces," the townships are the building blocks of counties and rural and regional municipalities. The district ("land district" in BC) is the equivalent of a county in a sparsely populated wilderness area, and any townships surveyed within its boundaries form only a small proportion of its total area. Since counties and rural municipalities are composed of townships, their boundaries are surveyed during the opening of the township lines forming their boundaries.

District boundaries are rarely surveyed except where they coincide with a provincial or county boundary. Provincial and territorial boundaries, except between Québec and Labrador and between the Yukon and the NWT, have all been surveyed. Canada's international boundary has been surveyed and marked on the ground, and the boundary markers are under continual inspection by the joint US-Canadian International Boundary Commission.

L.M. SEBERT

The Western Interior

In 1760 the land west of the Great Lakes was poorly mapped. HBC explorers such as Henry Kelsey, Anthony Henday and Samuel Hearne had been sent out on early exploratory journeys, and the La Vérendryes had been able to view only a fraction of the great land. Since none of them could make astronomic observations to fix their positions, they were able to produce only rough sketch maps or route descriptions.

In 1778 the HBC hired Philip Turnor, a trained inland surveyor. Turnor mapped the river routes across the company's vast holdings, and trained junior surveyors such as David Thompson and Peter Fidler in the art of field astronomy for position-fixing, and track-surveying for filling in map detail between the "peg points" provided by the astro-fixes.

By this time the HBC was in competition with the North West Company (NWC), which also had surveyors. Shortly after 1778 one of these surveyors, Peter Pond, discovered a practical canoe route from the prairie rivers over the Heights of Land into the Athabasca and Mackenzie rivers (see Portage La Loche). His 1785 map showing the route led other explorers such as Alexander Mackenzie and John Franklin into the central Arctic.

London map publishers made good use of the information flowing out of the fur-trade lands. By examining the resulting maps in their various editions, one can almost see the unfolding of Canada. One in particular stands out: "A Map Exhibiting All the New Discoveries in the Interior Parts of North America," published by Aaron Arrowsmith in 1795 and updated 19 times until after 1850.

In 1857, 2 scientific expeditions, one Canadian and the other British, were sent to the Canadian prairies. The British party under Captain John Palliser spent 3 years in the West. The Canadian expedition of Simon Dawson and Henry Hind concentrated on the country between Lake Superior and the Red River. Both expeditions gathered topographical and geographical data which were subsequently published on maps and in reports. These were influential in the negotiations preceding the purchase of Rupert's Land.

The West Coast

In 1774 Captain Juan Pérez Hernandez and his men aboard the Spanish ship Santiago were the first Europeans to view the Northwest Coast. Pérez had been dispatched there to counter the threat to Spanish sovereignty presented by the Russian expeditions of Bering and Chirikov along the Alaska coastline in 1741. He made several coastal sightings as far north as Dixon Entrance (54° N), but submitted no maps or detailed reports.

The following year Spanish hydrographer Juan Francisco de la Bodega y Quadra drew the first chart to show a portion of Canada's West Coast (see Spanish Exploration). James Cook arrived in 1778 to search for the western end of any channel that might connect with the Arctic Ocean, seen 7 years before by Samuel Hearne at the mouth of the Coppermine River, but he found no Northwest Passage.

The sovereignty of the West Coast was to remain in dispute for many years. While diplomatic negotiations were being conducted in Europe during the Nootka Sound Controversy, both Spain and Britain were allowed to make charts of the coast to support their claims.

The British work was done 1791-92 under Captain George Vancouver, and the Spanish hydrographers worked under Dionisio Alcalá-Galiano and Cayetano Valdés. There was no animosity between these groups, and on several occasions they exchanged data to improve the work on both sides.

In 1793 Alexander Mackenzie, a NWC explorer, travelled from Lake Athabasca to Pacific tidewater at the mouth of the Bella Coola River. During the next half century fur trade employees such as Thompson, Simon Fraser, Samuel Black and John McLeod made reconnaissance surveys into what is now central BC, increasing the knowledge of this rugged land and producing, in many cases, significant maps recording the topography of the area.

Land surveying began when HBC surveyor Joseph Pemberton arrived in Victoria in 1851. In 1858 he completed a map of Victoria. Gold had been found in the Fraser River, and before the year ended a full-fledged gold rush was in progress (see Fraser River Gold Rush). One section of a detachment of Royal Engineers consisting of 20 surveyors carried out a variety of tasks, including townsite surveys and topographic mapping.

By Confederation much of the BC northern interior was still unknown. The coastline had been surveyed, several routes through the mountains to the prairies were known, and military surveyors had mapped small areas in the south.

The Arctic

The truly remarkable accomplishments in the Arctic were 2 overland journeys: in 1771 Hearne reached the mouth of the Coppermine River at 67° N, and in 1789 Mackenzie descended the river that today bears his name to tidewater at about 68° N. As well, British navigators still sought the Northwest Passage by sea. Their fascination with this navigational will-o'-the-wisp culminated in the ill-fated Franklin Expedition of 1845.

During the ensuing attempts to find Franklin and his men, the searchers undertook further explorations. The resulting maps revealed the outline of Canada's mainland coast and disclosed the positions and shorelines of the major islands lying south of Lancaster and Melville sounds. Admiralty charts compiled from the navigational records of these voyages provided the most reliable geographical information about the region until after WWII. In fact, some of the aeronautical charts of northern Canada used during WWII showed little more than this information.

L.M. SEBERT