JF Ptak Science Books Quick Post
What struck me in this technical illustration is the cross-section of the ocean of air, and the attempt to depict the characteristics of the atmosphere in receding qualities of blueness. This seems a natural thing to attempt, but I can’t really remember seeing anything quite like this from the mid-19th century–sure there there are images showing the height of the atmosphere, but I just can’t recall the point being made in shades of blue. The image itself is a large detail from “Illustrations of Natural Philosophy, Pneumatics”, a colored lithograph by John Philipps Emslie, and made in 1851. This copy is from the Wellcome Collection, London, and try as I might I have not yet been able to find out in what book (if any) in which this work was published. Emslie was very active, and composed a number of complicated technical and data visualization efforts like this one, but I can’t yet find publication details. In the meantime, I’m posting this, concentrating on the atmosphere.
So far as the heights go in this image, we get through the troposphere and stratosphere, and most of the way through the mesosphere, and so far as the oxygen content goes at the various altitudes, the faded blueness for the relative ease of breathing air is fairly not-so-correct, but that’s not what the intention of the graphic was supposed to show…I was just trying to match-up the blueness with something besides height. The practical experience of humans in 1851 was extremely limited, the record ascension in a balloon at this point still stood at about 27,000′ and was made in 1837–the next big step would be in 1862 when the record was set at 39,000′, which was about 10,000′ higher than any mountain on Earth, the flight subjecting the aeronauts to the thrills of extremely low air pressure and cold. Anyway, the print does get its point across.
Source: the Wellcome Collection, https://wellcomecollection.org/works?query=John+Philipps+emslie#zpyyeaut
The full image:












SO, 18561 may have been tone of the earliest times that these 150+ lakes and islands of the Western and Eastern Hemisphere were ever been printed on the same page and in the same scale exclusive of their associative land masses and placed contiguously, side-by-side. They were, of course, seen in a common perspective before on any world map, but I think that this is the first year in which the islands and lakes of the world were displayed without oceans and land masses, and the effect is a little odd. If you take away the color and the text the image takes on a very definite biological flavor (I keep thinking of that tiny bone in the ear for the small lakes…) In any event it is far easier to compare these features without the distractions of the non-lakes and non-islands clouding and confusing our perspective fields.
