Apian - Folium Populi - 1533

FIRST EDITION - THE TALISMAN OF THE SCIENCES OF THE HEAVENS: PIETRO APIANO'S HARMONIC INVENTION
Folium Populi is one of the most curious and rare works by Pietro Apiano, renowned mathematician, astronomer and cosmographer of the German Renaissance. Published in Ingolstadt in 1533, it describes and illustrates a particular paper instrument in the shape of a poplar leaf, conceived to perform astronomical, astrological, and perspective calculations. The work, enriched by spectacular woodcuts, fuses mathematical precision with symbolic imagination, revealing the Renaissance tension between science and magic-number art. It is not merely a technical manual, but a true object of wonder, in which the instrument intertwines with the representation of power and with heraldic and allegorical images.
MARKET VALUE
The Folium Populi by Apiano is extremely rare on the antiquarian market. Complete copies, especially in good condition, today reach values ranging from 1,000 to 5,000 euros. Copies with illustrious provenance or in excellent condition can exceed these estimates, as early and unique evidence of Renaissance scientific ingenuity.
Rare Book Hub reports the sale of a copy for CHF 8,125 (about €8,000) within an estimate of 8,000–12,000 CHF.
Another sale at a Swiss auction house indicated an estimate of CHF 5,000–8,000 (approx. €5,150–8,250).

PHYSICAL DESCRIPTION AND CONDITION
Modern binding in stiff brown carton. Title page with a large illustrated woodcut and red and black text. Minor traces of oxidation. Pages (4); 22 numbered; (4).
First edition, in Latin and German, of Apiano’s description of his recently invented leaf-shaped sundial. This instrument can be used to calculate the hours of the day, the hour of dawn and sunset, and the so-called Jewish hours, which divide the time between dawn and sunset into 12 parts. The splendid woodcuts were executed by Hans Brosamer (ca. 1500–1554), with his monogram on the title woodcut beside the image of a cutter’s knife.
The title in the present copy is in an incorrect state, with “RFCENS” and “RFDACTUM” for “RECENS” and “REDACTUM”.
Small wood-borer holes touching the incipit, otherwise an excellent copy with wide margins.
Text in Latin and German, title page in red and black with a large finely executed woodcut by Hans Brosamer showing a diagram of the instrument beside an European and a Ottoman astronomer, each holding an astronomical instrument; a near full-page woodcut of the dedicatee’s coat of arms, JG di Loubenberg; a large woodcut diagram printed twice (in the Latin and in the German text); and 7 decorative initials. Folding plate, included in a very limited number of copies, here reproduced on antique paper.

FULL TITLE AND AUTHOR
Folium populi. instrumentum hoc a Petro Apiano iam rfcens [sic] inventum, et in figuram folii populi rfdactum [sic] per radios solis toto orbe horas cõmunes ostendit, ex quibus horæ ab ortu & occasu solis, deinde etiam horæ judeorum, .In disem newen Instrument, das die Form unnd Gestalt hat eines Blats, werden durch den Sonnen scheyn, in der gantzen Welt gefunden die gemaine Stunden des Tages, und auß der Selbigen, vermittels dises Blats magst du die Stunden vom Auff und Nidergang der Sonnen, des geleichen die Judenstund . leichtlich erkhennen.
[Ingolstadt] : [Peter Apianus], [s.d.]
Excusum Ingolstadii, 22 die Mensis Octobris 1533). - [12] c., 1 c. di tav. ripieg. : ill. ; fol. .
Peter Apian.

CONTEXT AND SIGNIFICANCE
The Folium Populi is an extraordinary work that exemplifies Renaissance capacity to transform science into visual spectacle. It is a movable sheet, articulated in geometric shapes, that allowed calculations related to the movement of the stars and judicial astrology. The title itself recalls the poplar form, a symbol of versatility and connection between earth and sky. The work fits within the line of Renaissance scientific inventions that fused practical utility, didactic value, and magical-symbolic dimension. For its combination of science and image, the Folium Populi stands as one of the most original creations of Ingolstadt University printing.

The Folium populi by Peter Apian from 1533 is equipped with a movable arm, a plumb line, a pearl, and two sighting devices. It resembles a poplar leaf with a stem. It is used to determine equal and unequal hours, as well as hours elapsed since dawn and sunset.
However, it no longer appears in Apian’s “Book of Tools”; it was replaced by one of the most useful dials: the Horoscope.
It is striking for its sophisticated design and its unique form. In contrast to the apparently austere and functional dial, it seems created more as a work of art.

The dedication page of the small bilingual opus “Folium Populi” to the “Nobilissimo Dño IO. GVLIELMO a Loubemberg”, whose coat of arms depicts three poplar leaves, is repeated in Apian’s even more important preliminary work, the “Instrument Book”.

BIOGRAPHY OF THE AUTHOR
Peter Apian (1495–1552), Latinized Apianus, was a German mathematician, astronomer and cartographer. Born in Leisnig, he studied in Leipzig and Vienna, publishing important works on cosmography, cartography and scientific instruments. Among his major works are Cosmographicus liber (1524), translated into many languages, and the Astronomicum Caesareum (1540), a masterpiece of Renaissance science. Professor at Ingolstadt, he received the support of Charles V. The Folium Populi represents an experimental phase of his inventive genius.

In 1526, Peter Apian founded his own typography in Ingolstadt. From 1527 onward, he taught at the university and was known as “PETRVS APIANVS de Leysnick Mathematicus Ingolstadianus”.
In 1532 the book on the quadrant “Quadrans Apiani” was published, followed in 1533 by the “Folium Populi”, by the “Horoscopion” and by the “Instrument Book”.

The latter represented a summary and partial integration of all individual publications previously issued on his measuring instruments. It was written in German and therefore addressed to an educated but not university audience.

PRINTING HISTORY AND CIRCULATION
Printed in Ingolstadt in 1533, the Folium Populi had a limited edition and was destined for a narrow audience of scholars, mathematicians and princely courts. Due to its technical nature and the complexity of the illustrations, its circulation was quite limited. Today very few copies are known in public libraries; its appearance on the antiquarian market is exceedingly rare and always of great resonance.

BIBLIOGRAPHY AND REFERENCES
Zinner, Astronomische Instrumente des 16. Jahrhunderts, Leipzig, 1957
Adams, Catalogue of Books Printed on the Continent of Europe, 1501–1600 in Cambridge Libraries
Houzeau-Lancaster, Bibliographie générale de l’astronomie
VD16 A 3092
OCLC/WorldCat, record Folium Populi, Ingolstadt 1533