Urania's Mirror illustrates 79 constellations on 32 separate cards. Some of the illustrated constellations are now obsolete, as are some of the subconstellations, such as Caput Medusæ (the head of Medusa, carried by Perseus).^[2] Urania's Mirror was originally advertised as including "all the constellations visible in the British Empire",^[1][4] but, in fact, it left out some southern constellations. By the second edition (1825), advertisements merely claimed illustration of the constellations visible from "Great Britain".^[4] Some cards focus on a single constellation, others include several, with Card 32, centered on Hydra, illustrating twelve constellations (several of which are no longer recognised). Card 28 has six, and no other card has more than four.^[2] Each card measures 8 inches by 5+1⁄2 (about 20 by 14 cm).^[4] A book by Jehoshaphat Aspin entitled A Familiar Treatise on Astronomy (or, to give its full name, A Familiar Treatise on Astronomy, Explaining the General Phenomena of the Celestial Bodies; with Numerous Graphical Illustrations) was written to accompany the cards.^[2] The cards and book came in a box illustrated with a woman almost certainly intended to be Urania, muse of astronomy.^[4] The cards and book were originally published by Samuel Leigh, 18 Strand, London,^[4] although, by the fourth edition, the publishing firm had moved to 421 Strand and changed its name to M. A. Leigh.^[5]

P.D. Hingley calls Urania's Mirror "one of the most charming and visually attractive of the many aids to astronomical self-instruction produced in the early nineteenth century".^[4] On its main gimmick, the holes in the stars meant to show the constellation when held in front of a light, he notes that, as the size of the holes marked correspond to the magnitude of the stars, a quite realistic depiction of the constellation is provided.^[4] Ian Ridpath mostly concurs. He describes the device as an "attractive feature", but notes that, due to the light at the time being provided primarily by candles, many cards likely burned up due to carelessness when trying to hold them in front of the flame. He notes three other attempts to use the same gimmick—Franz Niklaus König's Atlas céleste (1826), Friedrich Braun's Himmels-Atlas in transparenten Karten (1850), and Otto Möllinger's Himmelsatlas (1851), but states that they lack Urania's Mirror's artistry.^[2]

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  A Celestial Atlas, Plate 7
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  Urania's Mirror, Plate 10

The depictions of the constellations in Urania's Mirror are redrawings from those in Alexander Jamieson's A Celestial Atlas, published about three years earlier, and include unique attributes differing from Jamieson's sky atlas, including the new constellation of Noctua the owl, and "Norma Nilotica" – a measuring device for the Nile floods – held by Aquarius the water bearer.^[2]

Advertisements for Urania's Mirror, as well as the introduction to its companion book A Familiar Treatise on Astronomy, credit the design of the cards simply to a "lady", who is described in the introduction of the book as being "young". This led to speculation as to her identity. Some proposed prominent female astronomers such as Caroline Herschel and Mary Somerville, others credited the engraver Sidney Hall.^[4] The designer's identity remained unknown for 170 years. In 1994, while archiving early election certificates used to propose people to be admitted to the Royal Astronomical Society, P. D. Hingley found one proposing the Reverend Richard Rouse Bloxam and naming him as "Author of Urania's Mirror".^[3] While he had several notable sons, he has no other known publications, his main distinction being to have served as assistant master at Rugby School for 38 years.^[3]

The reasons for the disguise are unknown. Hingley notes that many contemporary publications attempted to suggest women had played a role in their creation, perhaps to make them sound less threatening. He suggests that anonymity might have been necessary to protect Bloxam's position at Rugby, but notes Rugby was quite progressive, which makes this unlikely; and, finally, suggests modesty as a possibility.^[6] Ian Ridpath, noting the plagiarism of the art from A Celestial Atlas, suggests that this alone might be sufficient to cause the author to wish to remain anonymous.^[2]

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  First edition "Pisces", without stars in the surrounding constellations. "Plain".
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  Second edition "Pisces", with the surrounding stars. "Fully coloured".

A December 1824 advertisement, which states the cards were "just published", offered the cards "plain" at £1/8s or "fully coloured" for £1/14s.^[1] This first edition did not include any stars surrounding the named constellations, leaving those parts blank. This was changed for the second edition, which added back stars around those constellations.^[2] An American edition was published in 1832. Modern reprints were produced in 1993, and Barnes & Noble reproduced the American edition (with accompanying book) in 2004.^[2] The accompanying book, A Familiar Treatise on Astronomy by Jehoshaphat Aspin went through at least four editions, with the last coming out in 1834.^[2] The second edition featured a marked expansion in content, growing from 121 pages in the first edition to 200 pages in the second.^[4] The book, by the time of the 1834 American edition, consisted of an introduction, a list of the northern and southern constellations, a description of each of the plates, with the history and background of the constellations depicted, and an alphabetical list of named stars (such as Achernar) with their Bayer designation, magnitude, and respective constellation.^[7]

A "Second Part" of Urania's Mirror, which was to have included illustrations of the planets and a portable orrery, was advertised,^[8] but no evidence exists to show it was ever released.^[2]

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  Plate 1: Draco and Ursa Minor
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  Plate 2: Camelopardalis, Tarandus and Custos Messium
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  Plate 3: Cassiopeia
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  Plate 4: Cepheus
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  Plate 5: Gloria Frederici, Andromeda, and Triangula^[9]
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  Plate 6: Perseus and Caput Medusæ
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  Plate 7: Auriga
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  Plate 8: Lynx and Telescopium Herschilii
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  Plate 9: Ursa Major
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  Plate 10: Boötes, Canes Venatici, Coma Berenices, and Quadrans Muralis
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  Plate 11: Hercules and Corona Borealis
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  Plate 12: Taurus Poniatowski, Ophiuchus, Scutum Sobiesky, and Serpens
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  Plate 13: Delphinus, Sagitta, Aquila, and Antinous
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  Plate 14: Lacerta, Cygnus, Lyra, and Vulpecula and Anser
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  Plate 15: Pegasus and Equuleus
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  Plate 16: Aries and Musca Borealis
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  Plate 17: Taurus
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  Plate 18: Gemini
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  Plate 19: Cancer
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  Plate 20: Leo Major and Leo Minor
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  Plate 21: Virgo
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  Plate 22: Libra
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  Plate 23: Scorpio
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  Plate 24: Sagittarius and Corona Australis, Microscopium, and Telescopium
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  Plate 25: Capricornus
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  Plate 26: Aquarius, Piscis Australis & Ballon Aerostatique
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  Plate 27: Pisces
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  Plate 28: Psalterium Georgii, Fluvius Eridanus, Cetus, Officina Sculptoris, Fornax Chemica, and Machina Electrica
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  Plate 29: Orion
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  Plate 30: Canis Major, Lepus, Columba Noachi & Cela Sculptoris
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  Plate 31: Monoceros, Canis Minor, and Atelier Typographique
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  Plate 32: Noctua, Corvus, Crater, Sextans Uraniæ, Hydra, Felis, Lupus, Centaurus, Antlia Pneumatica, Argo Navis, and Pyxis Nautica

The constellations depicted, in the order they are listed on the cards, are:^[2]

In addition, Mons Mænalus is shown below Boötes, Caput Medusæ is shown as part of Perseus, and Cerberus is shown with Hercules.^[2]

• "Urania's Mirror". Treasures of the RAS. Royal Astronomical Society. Includes a video presentation of the cards.