English Naturalist John Hill Named Leech Constellation Hirudo in 1754

Summary: English naturalist John Hill named Hirudo the Leech constellation in his 1754 astronomical dictionary, Urania, or, A Compleat View of the Heavens.

John Hill's Hirudo the Leech constellation (upper left) inhabits the northern celestial hemisphere's first quadrant (NQ1) as its only John Hill-created constellation and neighbors with Orion the Hunter and Taurus the Bull: Ultima Thulean, CC BY SA 4.0 International, via Wikimedia Commons

Eighteenth-century English apothecary, naturalist and writer John Hill introduced Hirudo the Leech constellation in his astronomical dictionary, Urania, or, A Compleat View of the Heavens, published in 1754.

"A conſtellation offered to the aſtronomical world," explained Hill (1714-Nov. 21, 1775) with an epithet that he repeated to introduce each of his 14 additional invented constellations. He standardly appended to the introductory phrase a brief description of the new constellation's locational composition. Accordingly, he added: ". . . and compoſed of a ſeries of conſpicuous unformed ſtars over the head of Orion."

Hill discerned in the starry composition above hunting Orion's head a leech. He spelled the common name for the members of the Hirudinea subclass of segmented worms as "Leach," even though the double e ("ee") spelling prevailed in his description of four species of the Hirudo genus (pages 16-17) in An History of Animals: Containing Descriptions of the Birds, Beasts, Fishes, and Insects, of the Several Parts of the World; and Including Accounts of the Several Classes of Animalcules, Visible Only by the Assistance of Microscopes, published in 1752.

Hill's description referenced the usage of the species as medicinal leeches. "The creature, under whoſe out-line theſe ſtars are arranged, is the common Leach; the inſect uſed in bleeding; common in ſhallow waters, and deſcribed by all the writers on natural hiſtory," Hill summed.

The celestial representation configures the leech's "ordinary" bent position rather than an outstretched posture. "It is repreſented under the figure of that animal, not ſtretched out at length, but in its ordinary poſition bent, and with the head directed back again toward the tail," Hill described.

The largeness and smallness of the composite stars correspond perfectly with the leech's variously sized anatomy. "The ſtars are very happily comprehended under the lines of this figure, and there is this peculiar advantage, that as a part of them are much larger than the others, thoſe are all diſpoſed toward the tail, and the ſmall ones run in a ſeries along the part toward the head, which, when the creature extends itſelf, is much the ſmaller part of its body," detected Hill.

Two constellations neighbor Hirudo the Leech, according to Hill's design. Orion the Hunter and Taurus the Bull surround the new constellation. "The conſtellations between which the Hirudo is placed are Orion and the Bull, and theſe are ſo diſpoſed that there are no others that can properly be called in to aſcertain its place. The lion's ſkin in the left hand of Orion is help up to the knee of the Bull, and his club is in ſuch a poſition as to come very near the top of the horn; by this means, between the two arms of Orion and the front of the Bull, there is left a ſpace vacant, and in that part of this ſpace, which is juſt over the head of Orion, ſtands the new conſtellation," Hill perceived.

Hirudo the Leech's tail and widened body near the back of Orion's head and his club. Hirudo's downward-bending head faces the top of the Hunter's head. "Its tail, or larger extremity, is near the back part of the head of Orion, the thicker portion of its body runs parallel with the club in his right hand, and . . . the head is bent again downwards, and is pointed toward the crown of Orion's head, but at a greater diſtance than the tail."

Although diminutive, constellation Hirudo encompasses a bevy of stars. "It is a ſmall conſtellation; but in proportion to the little ſpace that it occupies in the heavens it contains a conſiderable number of ſtars."

John Hill's Hirudo the Leech constellation emerges from unformed stars near the head of Orion the Hunter constellation in the northern celestial hemisphere's first quadrant (NQ1); John Hill, Urania, or, A Compleat View of the Heavens (MDCCLXVIII [1768]): via Internet Archive

Hill tallied 20 "conſpicuous ſtars" in Hirudo the Leech constellation. Nine construct the figure's upper shape, with one in the head, and, at a distance, a cluster of six, and then, at a distance, a set of two. Of these nine, eight "are of the ſmallest magnitude that can be called conſpicuous; there is a ninth among them a little larger, but it owes its ſeeming ſize to their particular littleneſs." Two stars separately tracing the outer outline of Hirudo's thickened mid-body are "larger . . . nearly the ſame ſize." A star that opposes the second of the two outer stars to outline Hirudo's inner outline sequences diagonally with two other stars. Then, five stars form two clusters, with three marking the outer side and two shaping the inner side of Hirudo's lower body. The constellation's 20th star makes a dramatic solitary appearance. "The twentieth is a ſingle ſtar, and is placed in the centre of the hollow of the tail."

Eight of Hirudo's 20 stars are identified by David Harper, once an astronomer specializing in celestial mechanics and positional astronomy but now a genome researcher, and his wife, astronomer L. (Lynne) M. Stockman, in "Hirudo -- The Leech," posted on their Obliquity website. The octet resides in Taurus the Bull: 111 Tauri (abbreviated 111 Tau), 115 Tau, 119 Tau, 122 Tau, 126 Tau, 130 Tau, 133 Tau, 134 Tau.

Hirudo occupies the northern celestial hemisphere's first quadrant (NQ1). The celestial leech is the only one of John Hill's six northern hemisphere constellations that resides in the first quadrant.

The International Astronomical Union (IAU) does not recognize Hirudo the Leech as an official constellation. Accordingly, Hirudo classifies as an obsolete constellation that also may be described as defunct, extinct, forgotten or former. Despite its lack of official status, however, Hirudo continues perch over Orion the Hunter's head for those stargazers who seek the leechy constellation.

John Hill equated his Hirudo the Leech constellation with Earth's common leech and noted the correspondence of the largeness and smallness of the constellation's "very happily comprehended" stars with the largeness and smallness of a leech's tail and head, respectively; depiction of "The Leach" (right), in John Hill, An History of Animals (1752), Plate 2, opposite page 30: Public Domain, via Biodiversity Heritage Library

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Dedication

This post is dedicated to the memory of our beloved blue-eyed brother, Charles, who guided the creation of the Met Opera and Astronomy posts on Earth and Space News. We memorialized our brother in "Our Beloved Blue-Eyed Brother, Charles, With Whom We Are Well Pleased," published on Earth and Space News on Thursday, Nov. 18, 2021, an anniversary of our beloved father's death.

Image credits:

John Hill's Hirudo the Leech constellation (upper left) inhabits the northern celestial hemisphere's first quadrant (NQ1) as its only John Hill-created constellation and neighbors with Orion the Hunter and Taurus the Bull: Ultima Thulean, CC BY SA 4.0 International, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Northern_Hemisphere_Hill's_Constellations.png

John Hill's Hirudo the Leech constellation emerges from unformed stars near the head of Orion the Hunter constellation in the northern celestial hemisphere's first quadrant (NQ1); John Hill, Urania, or, A Compleat View of the Heavens (MDCCLXVIII [1768]): via Internet Archive @ https://archive.org/details/bim_eighteenth-century_urania-a-new-astronom_hill-john-m-d-calli_1768/page/2/mode/1up; Ultima Thulean, CC BY SA 4.0 International, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Hirudo_Constellation.jpg

John Hill equated his Hirudo the Leech constellation with Earth's common leech and noted the correspondence of the largeness and smallness of the constellation's "very happily comprehended" stars with the largeness and smallness of a leech's tail and head, respectively; depiction of "The Leach" (right), in John Hill, An History of Animals (1752), Plate 2, opposite page 30: Public Domain, via Biodiversity Heritage Library @ https://www.biodiversitylibrary.org/page/56071239; Biodiversity Heritage Library (BioDivLibrary), Public Domain, via Flickr @ https://www.flickr.com/photos/biodivlibrary/50375462592/

For further information:

Broekmans, Onno D.; Jarlath B. Rodgers; William S. Ryu; and Greg J. Stephens."Resolving coiled shapes reveals new reorientation behaviors in C. elegans." eLife. Sep. 20, 2016.
Available via eLife @ https://elifesciences.org/articles/17227

Harper, David; and L. (Lynne) M. Stockman. "Hirudo -- The Leech. Unofficial Abbreviation: Hir. Genitive: Hirudinis. Origin: John Hill." Obliquity > Sky Eye > The Constellations > Extinct Constellations.
Available @ https://www.obliquity.com/skyeye/88const/Hip.html

Hill, John. "Hirudo." Urania, or, A Compleat View of the Heavens, Containing the Antient and Modern Astronomy, in Form of a Dictionary. London: T. Gardner, M.DCC.LIV [1754].
Available via Google Books @ https://www.google.com/books/edition/_/lzigAAAAMAAJ?hl=en
Available via Internet Archive @ https://archive.org/details/bub_gb_lzigAAAAMAAJ/page/n241/mode/1up

Hill, John. "Hirudo." Pages 16-17. An History of Animals: Containing Descriptions of the Birds, Beasts, Fishes, and Insects, of the Several Parts of the World; and Including Accounts of the Several Classes of Animalcules, Visible Only by the Assistance of Microscopes. London: Printed for Thomas Osborne, in Gray's-Inn, M.DCCLII [1752].
Available via Biodiversity Heritage Library @ https://www.biodiversitylibrary.org/page/56071478#page/34/mode/1up

Hill, John. "Insects Without Wings: Worms: The Leach." Plate 2, opposite page 30. An History of Animals: Containing Descriptions of the Birds, Beasts, Fishes, and Insects, of the Several Parts of the World; and Including Accounts of the Several Classes of Animalcules, Visible Only by the Assistance of Microscopes. London: Printed for Thomas Osborne, in Gray's-Inn, M.DCCLII [1752].
Available via Biodiversity Heritage Library @ https://www.biodiversitylibrary.org/page/56071239
Available via Flicker @ https://www.flickr.com/photos/biodivlibrary/50375462592/

Hill, John. Urania, or, A Compleat View of the Heavens, Containing the Antient and Modern Astronomy, in Form of a Dictionary. London: T. Gardner, M.DCC.LIV [1754].
Available via Google Books @ https://www.google.com/books/edition/_/lzigAAAAMAAJ?hl=en
Available via Internet Archive @ https://archive.org/details/bub_gb_lzigAAAAMAAJ/

Hill, John, M.D. [Urania]. A New Astronomical Dictionary, or, A Compleat View of the Heavens Containing Antient and Modern Astronomy Illustrated with a Great Number of Figures. London: T. Gardner, MDCCLXVIII [1768].
Available via Internet Archive @ https://archive.org/details/bim_eighteenth-century_urania-a-new-astronom_hill-john-m-d-calli_1768/

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Available @ https://earth-and-space-news.blogspot.com/2023/08/english-naturalist-john-hill-introduced.html

Marriner, Derdriu. "English Naturalist John Hill Named Bufo the Toad Constellation in 1754." Earth and Space News. Wednesday, Aug. 23, 2023.
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Available @ https://earth-and-space-news.blogspot.com/2023/08/naturalist-john-hill-named-tooth-shell.html

Marriner, Derdriu. "Naturalist John Hill Named Sea Horse Constellation Hippocampus in 1754." Earth and Space News. Wednesday, Sep. 27, 2023.
Available @ https://earth-and-space-news.blogspot.com/2023/09/naturalist-john-hill-named-sea-horse.html

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