Loving Lake Michigan

The Great Lakes are North America’s ecological crown jewels. Providing sandy beach and marsh shoreline as well as littoral, pelagic, and benthic habitats, and the largest freshwater lake system on the planet containing 21% of freshwater, the lakes support diverse life both in the water and within the watershed. The St Lawrence River supports still more riverine life. Their distinct shapes are visible from space, and their importance extends further to human populations, commerce, and more. With these substantial roles in mind, I am sure to look at the Great Lakes when inspecting a comparative view, either one of lakes or a rivers piece that includes lakes.

The Great Lakes take several morphologies on comparative maps. I use Lake Michigan as my benchmark and most of this post will focus on Lake Michigan, but it is not unique in its shape evolving. In lakes comparatives (some of rivers, too) dating to around 1850 or later, Lake Michigan takes its characteristic kidney bean shape; it is shown looking more like an eggplant prior to that. Further, on most rivers comparative views, its shape is all over the map (pun intended).

Lakes Comparative Views
Lakes comparative views are less common than their mountains and rivers cousins. That said, with even a few we can evaluate the differences among them. The most apparent difference to an American reader is the shape of Lake Michigan over time. As mentioned above, it goes from eggplant to bean shape over the course of twenty or so years.

Photo of Great Lakes detail of Carey and Lea's 1832 Principal Lakes. In this comparative map, Lake Michigan takes an 'eggplant' shape.
Great Lakes detail of Carey and Lea’s 1832 Principal Lakes. In this piece, Lake Michigan takes an ‘eggplant’ shape. (Photo: own work)

Knowing that the bean shape is true, you may wonder whether the cartographer simply made a mistake. I can dismiss this out of hand as maps contemporary to the said comparative also show the lake as straight. The other possibility is that the cartographer got it right vis-a-vis the information available at the time, and it was a true cartographic error (an inaccuracy in the map due to mistaken information available at the time); this is the most parsimonious explanation.

Photo of Comparative Sizes of Lakes and Islands. On this comparative view, Lake Michigan takes its true curved shape.
Great Lakes detail from Colton’s 1856 Comparative Sizes of Lakes and Islands. On this comparative view, Lake Michigan takes its true curved shape. (Photo: own work)

A review of later maps alongside other sources explains the change. In 1836 Michigan joined the Union and Wisconsin in 1848. These admissions required precise measurements of boundaries and a survey was performed, yielding the modern understanding of the lake. The Michigan Geological Survey, authorized by the state legislature on the day of its formation in 1836, is a candidate (still my hypothesis, I’m researching now to confirm) for the source of these revised maps.

Lakes on Rivers Comparatives
Lakes appearing on rivers comparative maps run the gamut from faithful renderings to examples of great license. Such is the case with depictions of Lake Michigan and there’s a simple reason for this. Rivers comparative maps are concerned with the length, and to some extent other physical characteristics; lakes, especially tangential ones, are of low priority. Considering the Lawrententian system extends from Duluth, through the great lakes, and along the St Lawrence to the Atlantic, Lake Michigan is not on the longest path. Any inclusion of it on a rivers comparative is more contextual than critical. To that end, cartographers can be excused for taking liberties with its orientation, size, or showing it at all.

Great Lakes detail of Mitchell’s 1860 ‘The World in Hemispheres’ (own work).

The reader will “get it” when reading one of these maps as they are coming in with the understanding that they are seeing rivers rather than lakes. This isn’t too say that showing lakes doesn’t add value, it does. The lakes aid the reader in identifying the river system, understanding the watershed, and appreciating the human population the system sports. When a river system’s orientation is changed, say so that it flows to the edge of the page, the lakes, also reoriented, assist the reader in realizing this.

Want to learn more about comparative views? Check out my free ebook!

© Peter Roehrich, 2016

Flipping Over the Great Lakes

I am pleased to add Mitchell’s 1860 The World in Hemispheres with Other Projections to my collection. This is principally a globular projection but instead of the vignettes that would have adorned a 18th century map, additional views fill the corners: the upper left and right corners have comparatives of the rivers of the western and eastern hemispheres, respectively.

Mitchell's 1860 'The World in Hemispheres.' Note comparative features in the upper corners.
Mitchell’s 1860 ‘The World in Hemispheres.’ Note comparative features in the upper corners (own work).

The use of comparatives in lieu of vignettes was common among 19th century maps, and we can infer from these that comparative views were perceived as worthy cartographic endeavors rather than mere curiosities. Page space was valuable, as evidenced by cartographers’ efficient usage of it, and easily could have been filled with other insets: select countries or cities, climate zones, or vegetation and animal life by region of the globe. Perhaps it was their role in commerce that made rivers an appealing feature to include; perhaps it was because many rivers were still being charted. What ever the reasons may be, they are beyond the scope of this analysis.

Instead, I’ll draw your attention to the orientation of the rivers. All western hemisphere rivers are depicted as emptying west to some sea off the left coast–the pacific ocean. Of course this is not accurate–although characteristic of comparatives, which took a vastly reductionist approach to compare the features by a single attribute–the Mississippi drains south into the Gulf of Mexico, the Amazon northeasterly into the Atlantic, the Potomac southeasterly into the Atlantic, and the Colorado south to the Sea of Cortez. The St Lawrence, subject of this analysis, flows east to the Atlantic.

Comparative detail of Mitchell's 1860 'The World in Hemispheres' (own work).
Comparative detail of Mitchell’s 1860 ‘The World in Hemispheres’. Note the Great Lakes on the St Lawrence (own work).

Looking closely at the St Lawrence, the Great Lakes are in the reverse order; the eastern most lake, Lake Ontario, is shown as though it’s the western most, and vice versa for Lake Superior. While these are out of geographical order (geographical order is not expected in a comparative, generally speaking), this reordering keeps them in relative order vis-a-vis the mouth of the river. But the cartographers took this reordering a step further, not only did they flip the order of the lakes, they also flipped the shapes of the lakes, engraving their mirror images. Looking closely at Lake Michigan, it’s characteristic bean shape is shown curving in the opposite direction.

Great Lakes detail of Mitchell's 1860 'The World in Hemispheres' (own work).
Great Lakes detail of Mitchell’s 1860 ‘The World in Hemispheres’ (own work).
Reflected Great Lakes detail of Mitchell's 1860 'The World in Hemispheres' (own work).
Reflected Great Lakes detail of Mitchell’s 1860 ‘The World in Hemispheres’ (own work).

The decision to flip the lakes’ shapes offers some important clues into the Mitchell’s purpose. First off, reflecting the images around the vertical axis shows that he intended to make the image as truthful as possible. It signals to the reader that he did not make a mistake in showing the flow of the river–that a cartographer would flip the direction of the river and the orientation of the lakes–is hardly parsimonious. Moreover, the Great Lakes are perhaps the most important aspect of the St Lawrence for its economic and transportation functions. The river, thanks to some canals, and more recently a system of locks and canals, affords the outputs of the midwest industrial infrastructure, including that of Chicago, as well as western Pennsylvania and New York, cheap access to the Atlantic. To that end, the reflection of the lakes assists the reader in locating the major industrial hubs on the lakes: Chicago, Erie, Buffalo, etc. A quick flip of the image in Pixlr reveals that the lakes are mirrored correctly.

The quirky illustration of the Great Lakes underscores the ingenuity of 19th century cartographers, skill of engravers, and their efforts to make comparative views valuable and useful to their readers.

I am happy to have purchased this map from Brian DiMambro.

© Peter Roehrich, 2015.

Styles of Comparing Rivers

I am pleased to add two new comparatives to my collection: A Map of the Principal Rivers shewing their Courses, Countries, and Comparative Lengths by the Society for the Diffusion of Useful Knowledge (SDUK)

Principal Rivers by SDUK, 1834. Rivers shown by direction of flow emptying into central sea. (Own work)
Principal Rivers by SDUK, 1834. Rivers shown by direction of flow emptying into central sea. (Own work)

Comparative Lengths of the Principal Rivers Throughout the World by Fielding Lucas,

Comparative Lengths of the Principal Rivers of the World by Lucas, 1823. (Own work)
Comparative Lengths of the Principal Rivers of the World by Lucas, 1823. (Own work)

of 1834 and 1823, respectively.

Lucas’ Comparative Lengths… is a very ‘conventional’ rivers comparative, where the rivers are shown sorted by continent, then by length, all draining into a representative body of water on the left. Of note is that the longest rivers of the Americas wrap, while the longest river of Africa is shown interrupted and truncated. What is to be gleaned from this? We can surmise that this is a matter of the author’s perception, right or wrong, that the rivers on this map of primary interest to the reader were those of the Americas, specifically the US. This map was clearly intended for a US audience and was published in Baltimore, MD. The treatment of the Congo & Niger as both interrupted and truncated tells the reader to be aware that there are long rivers in Africa, that the territory is unexplored, and that in the author’s mind they are of secondary importance.

American Rivers on Lucas' 'Comparative Lenghts'. (Own work)
American Rivers on Lucas’ ‘Comparative Lenghts’. (Own work)
African Rivers on Lucas' 'Comparative Lenghts'. (Own work)
African Rivers on Lucas’ ‘Comparative Lenghts’. (Own work)

In contrast to the above, the A Map of Principal Rivers … by SDUK is abstract and even surreal, even by the standards of comparative maps. It has an unusual sort, from my analysis it is sorted by the direction it drains, then by size. Interestingly, it shows all rivers emptying into a central water body. This might reflect an effort to highlight the interconnectedness of waterways. Further evidencing this is the inclusion of inland bodies of water, like Lake Michigan pictured with the St Lawrence, which are usually not shown on rivers comparative views. Alternatively, to focus on Lake Michigan, the inclusion of such a body might simply be a reflection of SDUK’s mission to provide the working class with scientific knowledge. Where Chicago was rapidly emerging as a center of industry in the early 1800s, it no doubt would have had a large working class who would have benefited from having a local point of reference. That said, SDUK was a British organization and their consideration of or distribution to American readers is unknown to me. Note that Lake Michigan is shown as straight rather than curved, as I’ve previously discussed (same engraver).

Nile detail of Principal Rivers by SDUK. (Own work)
Nile detail of Principal Rivers by SDUK. (Own work)
Great Lakes detail of Principal Rivers by SDUK. (Own work)
Great Lakes detail of Principal Rivers by SDUK. (Own work)
Central sea detail of Principal Rivers by SDUK. (Own work)
Central sea detail of Principal Rivers by SDUK. (Own work)

These lovely comparatives, one simple and one ornate, can tell us as much about their intended readers as they can about the understanding of the world at the time.

© Peter Roehrich, 2015

Principal Lakes

In my previous post I discussed my new comparative The Principal Lakes of the Western Hemisphere from Carey & Lea’s 1832 Family Cabinet Atlas. Well lightning struck again, I was lucky enough to find the map’s Eastern Hemisphere mate. In addition to being beautifully detailed and colored, these maps are excellent examples of true lakes comparatives (see my post where I bemoan lakes quasi comparatives).

Carey & Lea lakes comparative, eastern hemisphere. Note than most lakes are European.
Carey & Lea lakes comparative, eastern hemisphere, 1832. Note that most lakes are European.

First let me address the note at the top of these maps. It states that the lakes are in their proper position. I originally interpreted this to mean that northern lakes where shown to the top of the map, despite the larger maps being shown at the top. Upon close examination I determined the note to mean that the lakes were oriented so their north-south axis runs vertically on the page. Confusing. That said, upon inspection I saw Lake Maracaibo was positioned north of several North American lakes and Great Slave Lake to the left of the Great Lakes; this observation torpedoed any nagging doubt that their positioning was by size rather than geography. This is important: I hold that a defining quality of a comparative is that the features are arranged by the trait under comparison. I discuss the essential qualities of a comparative elsewhere, so I won’t go into that here.

Carey & Lea lakes comparative, western hemisphere, 1832.
Carey & Lea lakes comparative, western hemisphere, 1832.

The trait under comparison is not made explicitly clear, but as with a rivers comparative where the river length is the implicit basis, so too here the implicit basis is lake surface area. As I’ve mentioned before, there are several ways in which the lakes may be compared, again with area the most obvious. Of course they may also be compared by width, breadth, depth, even volume. And all of that operates under the (likely) assumption that principal is used to mean the largest, but that’s not the only possibility. Principal could be used to mean, for example, the lakes associated with the most commercial activity, or supporting the largest population (however that might be measured). However Carey & Lea defined principal, its interesting that Loch Leven, at a mere 8 square miles, made the Eastern Hemisphere map. On the other hand, Lake Victoria is conspicuously missing, however it wasn’t known to Europeans for another 20 plus years. More about how principal is defined and features chosen in later posts.

These maps are remarkably Eurocentric. The vast majority of the lakes on the Eastern Hemisphere map are European. A few in Asian countries, and one in Africa. While the lakes in Europe are also identified by the countries in which they’re located, Lake Chad is simply said to be in Africa, as though the continent is a monolith. Likewise, on the Western Hemisphere comparative the lakes are simply identified as North or South American.

Like its mate, I got this comparative from Brian DiMambro’s gallery.

© Peter Roehrich 2015

Plotting Lakes

Charts of lakes, and islands for that matter but I’ll restrict this analysis to lakes, often differ slightly in their format from those of mountains and rivers. Where the classic comparative is two dimensional, showing rank and size, some (but by no means all) charts of lakes are three dimensional, showing relative latitude and longitude and size.

Are charts of this flavor in violation of a cardinal rule of comparatives, that they must be arranged by size, rather than position on the Earth?

GW Colton's 1865 Comparative Size of Lakes and Islands
GW Colton’s 1865 Comparative Size of Lakes and Islands with characteristic Colton border. Note there is no clear organization by size, but rather lat & long. (Rumsey)

This is a matter of opinion, and there are good arguments that they are truly comparatives: first, I’ve never seen a lakes comparative where the largest lake was not the most prominent, and second, latitude and longitude are ancillary to showing size. But in my mind it’s clear that they do break this rule because rank is not abundantly clear, and that is the criteria by which they are to be compared.

Lakes comparatives have the unique problem of fitting irregularly shaped subjects unto a regular analytical landscape (no pun intended). That’s to say that lakes are not regular geometric figures all oriented in the same direction; their borders meander and their long axes run every which way. If they were regularly shaped, plotting them would be simple. The straight forward approach would be to place an illustration on a page plotted by their width and length on a Cartesian plane. That’s to say that the wider a lake is, the further to the right it is shown and the longer it is the further up it is plotted.

Of course, lakes are not polygons and this system is almost laughable. So what can be done to overcome this? Area is an attractive criteria. Lakes can be arranged on a page, say, starting in the upper left, working across in descending order, then returning to start a new row when the upper right is reached. This would mimic a common sort used for mountains. More complex, one could circumscribe a polygon over the lake, then arrange on a Cartesian plane as described in the ideal scenario above.

What about the criteria used for comparison? Is the largest lake that with the greatest area? That seems the logical choice, and what would easily be assumed by the reader. But other criteria could change the order markedly. What about greatest north to south or east to west span? Or, perhaps ranking the lakes by perimeter? Either of these latter criteria could allow a long skinny lake positioned with its long axis running northeast to southwest and with lots of coves and inlets to pop to the top of the list, ahead of a lake with much greater area. How about arranging by depth? To get down to brass tacks, a scatter arrangement is inappropriate when comparing lakes by either perimeter or depth.

© Peter Roehrich 2015