Plate II from <n>Thomas Wright</n>'s <n>An Original Theory or New Hypothesis of the Universe</n>, 1750.

Cover of <n>Physical Training for Business Men</n> (1917) by author <n>H. Irving Hancock</n>.

A chronophotograph from <n>Theodor Bergquist</n>'s 1913 book, <n>Swedish House-Gymnastics</n>.

A photomicrograph of the diatom <n>Heliopelta metii</n> by <n>Arthur E. Smith</n> from the 1909 book <n>Nature Through Microscope and Camera</n>.

A photograph from <n>Viktor Gustaf Balck</n>'s 1913 book, <n>Gymnastik med lek och idrott</n>.

Photograph from <n>J. G. Thulin</n>'s 1913 book, <n>Svensk husgymnastik från förr och nu</n>.

"Kopfkreisen" (head circles), a 1913 multiple-exposure photo from <n>Hus-gymnastik efter Lings system</n>.

Photograph from <n>Nils Sellgren</n>'s 1913 book on <n>Swedish House-Gymnastics</n>.

A photograph from <n>Theodor Bergquist</n>'s 1913 book, <n>Swedish House-Gymnastics</n>.

The <n>Legs Akimbo exercise</n> from the 1917 book <n>Physical Training for Business Men</n>. Photo by <n>A. B. Phelan</n>.

A 1917 chronocyclegraph from <n>Physical Training for Business Men</n>. Photo by <n>George J. Fisher</n> and <n>A. B. Wegener</n>.

A 1928 photogravure of an <n>Abyssinian Sage</n> by <n>Karl Blossfeldt</n> from his book <n>Urformen der Kunst</n>.

Photograph by <n>A. B. Phelan</n> from <n>H. Irving Hancock</n>'s <n>Physical Training for Business Men</n> (1917).

Photograph by <n>H. Irving Hancock</n> from his 1917 book, <n>Physical Training for Business Men</n>.

A chronophotograph from the 1913 book <n>Haus-Gymnastik für Gesunde und Kranke</n> by <n>Dr. med. A. A. A. Müller</n>.

<n>Shoulder Straightening with Towel</n> from the 1917 book <n>Physical Training for Business Men</n> by <n>H. Irving Hancock</n>.

Underside of a leaf from <n>William Sharp</n>'s 1854 series, <n>Victoria Regia; or, The Great Water Lily of America</n>.

An exercise from <n>Henrik Doring</n>'s 1913 book <n>Hus-Gymnastik</n> (House-Gymnastics).

A backward bending exercise from <n>Dr. med. A. Wide</n>'s 1913 book on <n>Swedish House-Gymnastics</n>.

An illustration from the 1913 edition of <n>Daniel Gottlieb Moritz Schreber</n>'s gymnastics manual, <n>Ärztliche Zimmergymnastik</n>.

A photograph by <n>A. B. Phelan</n> from the 1917 book <n>Physical Training for Business Men</n> by <n>H. Irving Hancock</n>.

A 1917 chronophotograph by <n>A. B. Phelan</n> from the book <n>Physical Training for Business Men</n>.

<n>Fencer</n>, a chronophotograph by artist <n>Georges Demeny</n>, ca. 1890.

A photograph from <n>J. P. Müller</n>'s 1905 book, <n>Haus-Gymnastik für Jedermann</n>.

An illustration from <n>Mori Yuzan</n>'s 1903 Japanese design guide, <n>Hamonshu</n>.

A chronophotograph from <n>Dr. med. A. A. Böhland</n>'s 1913 book, <n>Haus-Gymnastik für Gesunde und Kranke</n>.

A diagram of <n>Isander's dive</n> from the <n>Olympic Games of Stockholm 1912</n>.

<n>The Planet Saturn</n>, a chromolithograph by <n>Étienne Léopold Trouvelot</n> from an observation made in 1874.

<n>Ovipositor of female fly</n>, an illustration by <n>Martin Frobenius Ledermüller</n> from 1762.

Photograph by <n>A. B. Phelan</n> from <n>H. Irving Hancock</n>'s book <n>Physical Training for Business Men</n> (1917).

A 1928 photogravure by <n>Karl Blossfeldt</n> from his book <n>Urformen der Kunst</n> (Art Forms in Nature).

Photographic plate from the 1882 <n>Transit of Venus</n>, taken by an American expedition to Chile.

A chronophotograph of "Armrollen" from <n>Dr. J. G. Thulin</n>'s 1913 book, <n>Husgymnastik efter Ling-systemet</n>.

Plate 7 from <n>Augustus Bozzi Granville</n>'s <n>Graphic Illustrations of Abortion</n> (1834), by <n>Joseph Perry</n>.

A chronophotograph from <n>Physical Training for Business Men</n> (1917) by <n>H. Irving Hancock</n>. Photo by <n>A. B. Phelan</n>.

Chronophotograph from <n>Dr. med. A. C. Neumann</n>'s 1913 book <n>Haus-Gymnastik für Jedermann</n>.

<n>Rumpfbeugung</n> (Trunk bend), an exercise from <n>Henrik Kellgren</n>'s 1913 book on <n>Swedish House-Gymnastics</n>.