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KEPLER, JOHANNES. 1571-1630. :Tabulae Rudolphinae, quibus astronomicae scientiae, temporum longinquitate collapsae restauratio continentur. Ulm: Jonas Saur, 1627.
Folio (330 x 226 mm). Roman and italic types, double column, printed shoulder notes. Engraved allegorical frontispiece designed by Kepler, depicting Hipparchus, Ptolemy, Copernicus, Brahe, and Kepler gathered in the Temple of Urania, numerous woodcut diagrams in text, including a full-page of diagrams on k3v, woodcut initials, large woodcut device on part 2 section title. With the 4-leaves \"Sportula genethliacis missa\" (q4) printed in Sagan and dated 1629, inserted after the tabulae. Early 18th-century half-sheep and mottled boards, spine gilt in 7 compartments with red and green morocco lettering piece, red speckled edges, a few gatherings (including \"Sportula\", sig. q, issued in 1629) browned (as often). Provenance: Co. Riccati (Jacopo Francesco Riccati (1676-1754, Venetian mathematician; bookplate on title verso).

FIRST EDITION OF KEPLER\'S LAST LIFETIME PUBLICATION AND HIS CROWNING ACHIEVEMENT, THE \"FOUNDATION OF ALL PLANETARY CALCULATIONS FOR OVER A CENTURY\" (Sparrow). Third state, with second quire [):():(⁴] on different paper, albeit trimmed here to the same size as the adjacent leaves. \"The tables are extraordinarily important, for they document in a unique way Kepler\'s great contributions to astronomy\" (Gingerich). \"Besides the planetary, solar, and lunar tables and the associated tables of logarithms it includes Tycho Brahe\'s catalog of 1,000 fixed stars, a chronological synopsis, and a list of geographical positions ... Kepler was an astronomer\'s astronomer. It was the astronomers who recognized the immense superiority of the Tabulae Rudolphinae. For the professionals the improvement in planetary predictions was a forceful testimony to the efficacy of the Copernican system\" (Sparrow). Based on Tycho Brahe\'s observations, the tables were then supplemented by Kepler\'s own observations. The calculations were a major mathematical achievement, as of course, Brahe\'s data applied erroneously to \"perfect\" circular orbits. Kepler had discovered the true elliptical shape of the planetary orbits, and thus, had to recalculate everything according to his new laws. The printing history of the book, during the 30 years\' war, is quite complex. There were 1000 copies printed in Ulm in 1627, with three known states, affecting the title and the first two gatherings. Some copies are known with a posthumously published world map, and some have a posthumous appendix - neither is present in this copy. \"In excusing the long delay in publication... [Kepler] mentioned in the preface [p. 6] not only the difficulties of obtaining his salary and of the wartime conditions but also \'the novelty of my discoveries and the unexpected transfer of the whole of astronomy from fictitious circles to natural causes, which were most profound to investigate, difficult to explain, and difficult to calculate, since mine was the first attempt\'\" (DSB). Caspar 79; Gingerich Johannes Kepler and the Rudolphine tables; Houzeau and Lancaster 12754; Lalande p 190; Norman 1208; Sparrow 116.

开普勒，约翰内斯。1571-1630. 鲁道夫的桌子被称为天文学，包括餐厅倒塌的时间。乌尔姆：乔纳斯·索，1627年。

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西格马尔·波尔克，当代艺术I-

Sigmar Polke * - Zeitgenössische Kunst I-

(Oels/Niederschlesien 1942-2010 Cologne)
Untitled, 1994, on the reverse signed, dated twice S. Polke 94, natural resin and pigments (malachite, lapis lazuli and realgar) on canvas, 95 x 75 cm, framed

We are grateful to Michael Trier, Cologne, for his scientific advice in cataloguing this work.

Provenance:
Private Collection, North Rhine-Westphalia - directly from the artist
Van Ham Kunstauktionen, Cologne, 01 December 2021, lot 301 - acquired there by the present owner

Sigmar Polke has left us an extensive oeuvre, centred first and foremost on his irrepressible interest in colour. The production of colours was of great importance to the artist, who was often described as an alchemist, and he wanted to explore it from the bottom up. With the aid of the most modern techniques and motifs he was constantly searching for the origin of painting, sometimes also with a great deal of irony. Art ought to be an experiment with an open outcome, and he, the artist, ought to elicit the hidden beauty from the material world with his works.

Polke worked with the so-called \"Schüttbilder\" from the early 1970s on, colour samples and \"Probierbilder\", in which calculated chaos is elevated to a creative principle. Ten years later, Polke\'s painting showed a change \"that was much discussed in connection with the works for the exhibition Zeitgeist in 1982, for Documenta 7 in the same year and reached a climax in his contribution to the 德国 pavilion at the 42nd Venice Biennale (1986). Figuration recedes in favour of the more gestural and process-like use of colour, its lush or veil-like overlays and fusions.\"
(Katharina Schmidt, quoted from: Sigmar Polke – Zeichnungen, Aquarelle, Skizzenbücher 1962 – 1988, exh. cat., Kunstmuseum Bonn 1988, p. 194).

The 1994 work offered here is in the tradition of the colour samples of the 1970s and refers pictorially to the colour plates from 1992, which are in the Stedelijk Museum in Amsterdam. Its presentation is very painterly and overall reminiscent of the wall painting at the Venice Biennale (1986), for which Sigmar Polke was awarded the Golden Lion.

In the present work, the artist mixed a total of three dyes with natural resin and applied them to the canvas. In the lower area, the ultramarine blue of the dark blue semi-precious stone lapis lazuli dominates. Lapis lazuli is one of the oldest pigment stones of all and was already used as pigment in prehistoric Europe. For the upper part of the picture, Polke used the powdered pigment of the semi-precious stone malachite. The coarser the grain, the more intense the shade of colour. Malachite pigment was prized in antiquity as a cold green for wall paintings. It was used in panel paintings in the Renaissance. Next to green earths, malachite was the most important green pigment until the 18th century. On the left-hand side in the central area of the canvas, Polke painted an oval with the chemical pigment realgar. Realgar, also called ruby sulphur or ruby of arsenic, has a changing hue, which depends on the grind of the pigment. The darker shades are an orange-red, the lighter ones a yellow-orange, as seen in this painting. Although there are modern alternatives, Polke seems to have found processing the colours and pigments of the old masters with an awareness of modern times highly interesting.