What’s in a Name?

What’s in a name? What does it mean for a map to be titled a comparative? It’s been a while since I discussed the fundamentals of comparatives; this post reviews those but is by no means exhaustive.

I have developed a few criteria for comparative views. Comparative views must be: continuous depictions of geographic features, arranged by size (with a few exceptions), to show variation in size with an accurate scale, and usually have a human scale benchmark.

Possibly the first comparative view of the early style, showing mountains of the old and new worlds.(Own work)
Hohen der Alten by Bertuch, c1810. Possibly the first comparative view of the early style, showing mountains of the old and new worlds. (Own work)

A Brief History
Comparative views were inspired by Humboldt’s 1805 chart. Although it wasn’t a comparative, it planted the seed for visual display of altitude related data visually. Bertuch was the first to widely publish a comparative, c1810, in the form of a fictionalized landscape. This style gave way to the stylized graph format seen in most comparatives, often found in atlases. By the late 19th century comparative views had fallen out of favor.

Principal Mountains by Carey and Lea, 1832. This miniature map of mountains shows pyramids as a human scale benchmark.
Principal Mountains by Carey and Lea, 1832. This miniature map of mountains shows pyramids as a human scale benchmark. (Photo: own work)

Continuous
Comparatives must give the illusion of looking at a scene or “view” of geographic features. The first comparatives did this by taking the form of a landscape. Later comparatives, those of the graph style, achieved this through abstract means where the peripheral attributes of one feature blended into another; mountains slightly overlapped to form a range and rivers drained into a common body of water. Without this unity among the features, the comparison would hardly exist as it would be district images, not inviting the reader to compare them.

Five panel lithograph mountains and rivers comparative view.
Five panel comparative chart of mountains and rivers by Johnson. Note the graph like style, where mountains are simple cones. c1855. (Photo: Own work)

Arrangement and Scale 
A comparative view is a device to highlight the large (usually, although as always, there are exceptions) mountains, rivers, etc., of the world. As such, they must be laid out so that the reader can readily identify the largest of the objects. Employing (usually) a sorting methodology achieves this. Sorting so as to create a gradient, largest to smallest or vice versa, is common. Pyramid sorting is common with mountains, placing the largest mountain in the middle and the smaller ones to the sides, alternating. Scaling objects on a similar basis is essential to allow readers to evaluate their relative sizes.

The Great Pyramids and Paris as shown on Thomson & Lizars' A Comparative View.
The Great Pyramids and Paris as shown on Thomson & Lizars’ A Comparative View. The Great Pyramids serve as a human scale benchmark. (Photo: own work)

Human Scale Benchmark
Heights of very large objects like mountains are hardly meaningful without something of a translation. That translation is achieved through a benchmark that is an intermediary. Many comparatives use the Great Pyramids of Giza as such an intermediary; albeit large, pyramids are still on the human scale to the extent that they were built by hand, people can easily walk around them, and they can be scaled. Despite being on a familiar scale, their size is substantial enough to be compared to mountains.

More
Check out some of the great resources from David Rumsey, Geographicus, and Hautdidier.

© Peter Roehrich, 2016

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Mysterious Mountain Charts

A small group of mountains comparatives were made for seemingly industrial/scientific purposes, rather than for education of the general public as most of these unique antiquarian maps were. The distinction between the educational and orological (that is, pertaining to the study of mountains) styles literally being in the shape of the mountains and their target audiences.

The earliest mountains comparative views, between 1810 and the early 1820s, were fictionalized landscapes, followed by the convention adopted where mountains were depicted as fictionalized cones (I term this the educational style), this after the landscape style.

Possibly the first comparative view of the early style, showing mountains of the old and new worlds.(Own work)
Hohen der Alten by Bertuch, c1810. Possibly the first comparative view of the early landscape style, showing mountains of the old and new worlds. (Own work)
Five panel lithograph mountains and rivers comparative view.
Five panel educational style comparative chart of mountains and rivers by Johnson. Note the graph like style, where mountains are simple cones, c1864. (Photo: Own work)

A few orological comparative maps emerged, were the cartographer preserved the cross-section of the peak, at about the same time that the simplified cone shape became widespread.

This manuscript, by an unknown cartographer, c1824, shows mountains in Portugal in cross-section. (Photo: Own work).
This orological style manuscript map, by an unknown cartographer, c1824, shows mountains in Portugal in cross-section. Based on the work of von Eschwege. (Photo: Own work).

We can imagine the family tree of mountains comparatives branching in the 1820s with the educational and orological limbs diverging from the landscape trunk. In contemplating this split, in combination with the fact that the landscape style virtually died out, we can infer that simultaneously cartographers of different objectives learned of comparatives and incorporated the concept into pieces that met their distinct needs. The purpose of the educational style being to bring the public at large information about the heights of mountains, they gave dimension to figures previously relegated to tables, where a simple cone would suffice in illustrating the mountains. Conversely, the orological style was to document the physical properties, beyond altitude, of the peaks for use by an audience requiring more detailed information. The orological users may have required these charts for reasons related to mineral mining, among other plausible needs. The manuscript orological piece carrying von Eschwere’s data from his work in Portugal was likely prepared for mining purposes given his work.

Print of mountain ranges arranged by height.
Stieler’s orological style Known Heights Above Sea Level, c1855. Mountain ranges are shown one atop the next. (Photo: Own work).

Alternatively, it is possible that some of these orological charts were prepared for navigational purposes. Journeying across a continent on a scientific exploration, or perhaps laying a railroad, the heights of the mountains, and the locations of passes, would be of utmost importance. Evidence exists that these charts might serve such a purpose exists in their scale. The orological charts are often, if not always, of different scales horizontally versus vertically, meaning that the heights of mountains may be accurately represented, but not their widths. It stands to reason that a chart for use in planning a mine would maintain consistency between horizontal and vertical scales so as to accurately depict the mineral seam. The fact of differing scales may mean that the variation in height across the mountain may have been of utmost importance.

Orological style charts are few and far between–and this is in the context of the already obscure comparative genre. This is too bad. They are a unique application of a beautiful discipline of mapping. Moreover, they stand as testimony to the value of comparative views as more than delightful pictures, but as serious tools for documenting the surface of the for industrial purposes. But why were they drawn?

© Peter Roehrich, 2016

German Comparative Innovation

Comparatives were popular through most of the 19th century, published across western Europe, the United States, and later in Japan. Comparative views evolved constantly as new information became available, as publishers sought new ways to differentiate their atlases, and as new ideas in data visualization emerged. Whereas the works of European and American cartographers’ drove the changes in the genre, Humboldt, Bertuch, and Perthes were standouts as innovative German publishers of comparative views.

Black and white print c1840s of Chimborazo, inspired by Humboldt.
Physical Geography, c1840s partial reprint of Humboldt’s 1805 view of Mount Chimborazo. (Own work.)

Alexander von Humboldt shook up scientific data presentation when, in 1805, he published Geographic der Pflanzen in den Tropenlandern, ein Naturgemalde der Anden documenting his findings from his exploration of Mount Chimborazo in present day Ecuador. It was unique in that it displayed information corresponding to altitudes in relative position on a cross-section of a map. In the margins of the graphic he further annotated observations of physical phenomena and their corresponding altitudes. Where this style of visualization seems commonplace to 21st century information consumers, it was hardly such at the time; in the early 1800s visual display of data was in its infancy.

Possibly the first comparative view of the early style, showing mountains of the old and new worlds.(Own work)
Hohen der Alten by Bertuch, c1810. Possibly the first comparative view of the early style, showing mountains of the old and new worlds. (Own work)

Learning of Humboldt’s chart and inspired by Goethe, Friedrich Bertuch prepared his Hohen der Alten in about 1810, publishing it in his Bilderbuch, a children’s encyclopedic volume. That he published it at all, what he displayed, and that it appeared in a children’s book, are important facts. That he published it signifies the embrace of the Humboldt’s cross sectional style as a means of describing occurrences at various heights. His view took a landscape form, with mountains arranged as though viewed from afar, generally with the larger mountains to the sides and background of the image, but didn’t end there. Stick figures show Humboldt and de Suassure on Mounts Chimborazo and Blanc, respectively, a crocodile at sea level, and Gay-Lussac aloft on his record setting balloon flight. By going beyond just mountain heights to show human accomplishments, Bertuch both ties human scale and geologic scale, as well as uses the comparative as a device to showcase human accomplishment. Plants and animals appearing on the comparative pull forward the thread that Humboldt wove whereby mountains are re-imagined as not just inert monoliths, but as parts of dynamic, living systems. By including his view in a children’s book, he recognized that this genre makes complex information accessible in a simple and easy to understand format.

Print of mountain ranges arranged by height.
Perthes’s Known Heights Above Sea Level, c1855. Mountain ranges are shown one atop the next. (Own work.)

Die Benkannteren Hoehen uber der Meeres Flache in Transparenten Profilen by Perthes is unlike the other comparatives. Mountains comparatives typically show their subjects side by side in descending order or in an overlaid descending sort. Perthes, on the other hand, shows the mountains overlaid in transparency so that one can see the contours of the mountains instead of them being obstructed by the mountains in the foreground, or reduced to conic figures. This innovation is noteworthy in that it signifies an interest in the entire mountain, rather than the peak in isolation. It also represented an innovation built on the line graph, placing geographic location on the x-axis. Interestingly, and perhaps because Perthes published this as the comparative genre was at its apex, this style of comparative never took hold.

To be sure, these German cartographers (or scientist in Humboldt’s case) made great contributions to the comparative view as a style between inspiring, giving rise to, and redefining the charts. They by no means were the only innovators: Darton in 1823 produced the first compound comparative, showing both mountains and rivers in the same panel; the Society for the Diffusion of Useful Knowledge published a unique circular rivers comparative; and Mitchell was possibly the first to add comparative elements to globular projections. All told however, their pieces are testimony to the good work coming out of German cartography.

© Peter Roehrich, 2016

2015 Year-end Wrap-up

I hope you have enjoyed reading this blog as much as I’ve enjoyed penning it. With 2015 having come to a close, I am looking back on what this blog has accomplished: I’ve introduced the concept of a comparative, shown you some of what I believe are exemplary pieces, and drilled into a few of them to understand them better. I hope this endeavor had both entertained and educated. My goal, which I am renewing today, is to tell the captivating story of these beautiful Victorian pieces in a way that endears them to you as they are to me. My objectives for 2016 are to increase the frequency of my posts, to propose new ideas that further the understanding of comparatives, and to develop a virtual library of text and images. I want to leave you smarter for having read my blog and perhaps slightly intrigued. I’d like to revisit a few of my most favorite items from 2015–I hope you like them, too.

Mitchell’s 1860 The World in Hemispheres has an interesting mirror image of the Great Lakes and St Lawrence. Showing them in reverse order maintains their relative position to the mouth of the St Lawrence, shown flowing in the opposite direction, and allows the reader to find landmarks around the Great Lakes in their relative positions by flipping them

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).

Gay-Lussac’s flight to 23,000 feet in a balloon was quite a feat, in 1804, no less. Humboldt’s ascent of Mt Chimborazo to over 19,000 feet was also a technical milestone, and the data he collected a boon to science. It’s no wonder that these achievement appeared on mountains comparatives, they signaled man’s conquest over nature. Thomson and Lizars show both of these on their 1817 A Comparative View.

Gay-Lussac's 1804 balloon flight as shown on Thomson and Lizars' A Comparative View.
Gay-Lussac’s 1804 balloon flight as shown on Thomson and Lizars’ A Comparative View. Own work.
Humboldt's ascent of Chimborazo as shown on Thomson & Lizars' A Comparative View. Own work.
Humboldt’s ascent of Chimborazo as shown on Thomson & Lizars’ A Comparative View. Own work.

As the discipline of comparatives expanded, cartographers developed innovative techniques to show the features. This yielded two results: comparatives did a better job of showing their features (more features, more information, more intuitive, etc), and it allows cartographers to differentiate their products in the market. Lucas’s Comparative Lengths of the Principal Rivers and A Map of the Principal Rivers by SDUK illustrate both the variety and innovation among comparatives. Where Lucas’s chart is very straightforward, showing river lengths by continent draining westwardly, the SDUK comparative shows both river direction and length emptying into a central water body.

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)
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)

 

 

 

The most data-rich of the comparatives I covered this year are Tallis’s Comparative View of the Principal Waterfalls, Islands, Lakes, Rivers and Mountains of the eastern and western hemispheres. They include each of the 5 classes of features shown in comparatives and also range from the early tableau style popular among the earliest comparatives (the waterfalls panels) and move to the more developed format of later comparatives (mountains & rivers).

Tallis's 1851 'Comparative View...Western Hemisphere'. Note the change in styles of the panels and the condor over the mountains. (Own work.)
Tallis’s 1851 ‘Comparative View…Western Hemisphere’. Note the change in styles of the panels and the condor over the mountains. (Own work.)
Tallis's 1851 'Comparative View...Eastern Hemisphere'. Note the change in styles of the panels and the balloons over the mountains. Everest had not yet been mapped. (Own work.)
Tallis’s 1851 ‘Comparative View…Eastern Hemisphere’. Note the change in styles of the panels and the balloons over the mountains. Everest had not yet been mapped. (Own work.)

Thank you for your readership in this blog’s first year; you have brought valuable insights through your comments and direct messages and I hope to continue the dialog in the new year. May 2016 bring you health and happiness.

© Peter Roehrich, 2015

Scaling Rivers

In previous posts I have discussed the scaling of waterfalls and Johnson’s scaling of mountains in his 5 panel comparative. This post revisits that comparative to examine the scaling of the rivers.

image
Comparative Heights of Mountains and Lengths of Rivers (Johnson from David Rumsey).

This is an innovative comparative in that it follows the Mountains and Rivers approach pioneered earlier in the century, but splits the features out by continent. This allows the reader to see the range in heights of the peaks within each continent. The same is true of the rivers aspect; the rivers are first grouped by continent, then sorted by length. Breaking the view into panels allows him to show more features and begets ready comparison within the continental grouping.

This approach carries with it a major hazard, however: the increase in resolution and organizational capabilities of this display, because it doesn’t maintain a constant scale across the panels, comes at the cost of distorted heights and lengths between continents. Where mapping is a discipline of tradeoffs, the impact of this is dependant on the purpose of this comparative.

We can envision several candidate reasons Johnson included this comparative in his atlas. The first, and most simple is to document the sizes of mountains and rivers around the world visually. The second, which piggybacks on the first, is to display the size statistics but to animate them with drawings. We can compound both of these objectives by considering whether he wanted to show the diversity within continents or across them.

In the case of the second reason, to show otherwise dry statistics in a more intuitive display, the distortion between panels is less important because the image is merely a scaffold to support the numerical height or length description. Whether he hoped the reader would compare within or across continents we’ll examine further down.

As to the first proposed reason, to visually display the heights/lengths, with the statistics playing second fiddle, the distortion is much more important, and distorted they are!

image
River exaggeration between panels on Johnson's comparative (own work).

In Johnson’s comparative view the longest rivers of each continent (which I am terming “index” rivers) are all shown to be about the same length, within about 10% or so, while their stated lengths vary by as much as about 90%. When their differing scales are compared, the Volga, the smallest of the index rivers, is overstated by 70%.

If his motivation was to show variation within the rivers of each continent, this scale distortion is confusing but necessary as magnifying the shorter Volga makes it easier to perceive its size vis-a-vis the other European rivers. On the other hand, if his purpose was to show the differences in lengths across the continents, this is a disservice to his readers at best, if not downright dishonest.

But would he intend his readers to compare the rivers’ lengths across continents? Probably not. The first evidence for this is that each continent’s rivers are compartmentalized to distinct panels. The second piece of evidence to this end is the alternating sort direction: longest to shortest in the first panel, shortest to longest in the second, and so on. Because the rivers are stacked and alternating, the evaluation of the index rivers between panels is difficult, versus the side by side presentation of most mountains and rivers charts (which he’d previously published). Johnson without doubt knew this layout would make intercontinental comparison difficult and would not have chosen it had he wished for the reader to draw such comparisons. As for whether he sought to intentionally mislead the reader, it’s an intriguing proposition, and we may never know for sure, but we can easily dispute it as both not parsimonious and, as someone who relied on his reputation as a reliable authority on geography, playing with fire.

© Peter Roehrich, 2015

Gay-Lussac’s Balloon Flight

Joseph-Louis Gay-Lussac’s balloon flight of 1804 is featured in several early to mid-19th century comparative views. I invite you to read my discussions of Thomson and Lizar’s comparative showing his balloon and and of the differing altitudes shown on across comparatives of the day.

Gay-Lussac's 1804 balloon flight as shown on Thomson and Lizars' A Comparative View.
Gay-Lussac’s 1804 balloon flight as shown on Thomson and Lizars’ A Comparative View. Own work.

 

 

On September 16, 1804, following a flight in the previous month with fellow scientist Biot, Gay-Lussac launched his balloon in Paris on a dual purpose scientific and publicity mission. He stayed aloft for 6 hours, landing in St. Gourgon. At the time, hot air and gas filled balloon technologies competed. Each had advantages and short comings. Charles and Robert’s hydrogen filled balloons retained their buoyancy as the gas cooled although they were prone to explosion. The Montgolfier hot air balloon wasn’t filled with an explosive gas, but required the pilots to stoke fires to prevent the air from cooling (a good thing that the gas was not flammable as embers from the fire had a tendency to ignite the envelope!).

Gay-Lussac launching Sep 19, 1804. (Photo credit: Smithsonian)
Gay-Lussac launching Sep 19, 1804. (Photo credit: Centennial of Flight/Smithsonian)
Early balloon designs. Montgolfier's hot air design is shown center of top row and Charles and Robert's center of the lower row. (Photo credit: Library of Congress)
Early balloon designs. (Photo credit: Library of Congress)

Gay-Lussac’s balloon was smaller than that which he used for his 2 person flight from the previous month to 3,000 m. From contemporary illustrations we see that it was a hydrogen balloon of the Charles & Roberts design.

Fragment of Gay-Lussac's balloon envelope.
Fragment of Gay-Lussac’s balloon envelope. (Photo credit: Library of Congress)

I have found few records of his flight, and particularly sparse descriptions of his preparations or supplies. As it was a hydrogen gas balloon, it’s unlikely he brought any form of open flame as a source of heat. Beyond the obvious, using a flame to warm his body, he could also use a heat source to drive a reaction where an oxygen containing compound decomposes, liberating the oxygen as gas. Hydrogen was well known to be flammable; the prospect of an ember striking the gas bag would be terrifying as it would be disastrous. Other compounds can be mixed to release oxygen, but these reactions are exothermic, meaning they release heat, and would again be a risky provision on such a lighter-than-air flying machine. Regardless, something for warmth would have certainly benefited him. The surface temperature in Paris was about 28°C (82°F), dropping to nearly -10°C at altitude.

He did carry several instruments. He recorded temperature at several points along his ascent, so we can infer that he carried a thermometer, likely mercury. He also carried a hygrometer (de Saussure variety, where a piece of human hair is connected to a needle, applying differing tension on the needle according to humidity) and observed decreasing humidity as he ascended. Gay-Lussac carried some kind of flasks or bottles to collect air samples. To measure altitude, we can infer that he carried a barometer, although perhaps he used triangulation to determine his altitude.

We know that Gay-Lussac carried bread based on his account that his mouth was too dry from the low humidity to eat. His eagerness to go as high as possible is recalled in a charming anecdote. Upon reaching 7,000 m and wanting to climb higher, he jettisoned a white, wooden chair. Being so high, his balloon was not visible from the ground, so when the chair plopped down next to a shepherd woman, she concluded it was of divine origin. Not until he relayed that he threw it overboard to and it was published by the press, was the true origin known.

Gay-Lussac’s altitude record stood for nearly 50 years.

© Peter Roehrich, 2015.