MATHEMATICAL INSTRUMENTS--INTEGRATORS AND INTEGRAPHS, A COLLECTION OF SIX WORKS, 1815-89

i. Abdank-Abakanowicz, Bruno (1852-1900). Les Intégraphes: la courbe intégrale et ses applications. Paris: Gauthier-Villars, 1886, 8vo, numerous figures, calf backed marbled boards [T&W A1]ii. Abdank-Abakanowicz, B., Bitterli, Emil, translator. Die Integraphen. Leipzig: B.G. Teubner, 1889, 8vo, numerous figures, later marbled boards, with an autograph letter signed by the author to the translator loosely inserted, in French, 1888, and the translator's contract signed by the publisher, 1886, (bought from Antiquariat W. Geisenheyner, Münster, 2006), [not in T&W]iii. Boys, Charles Vernon (1855-1944). "Calculating machines" [in:] Journal of the Society of Arts, vol. 36, no. 1737, March 3, 1886. 8vo, boards, (bought from Yelm Books, 1999), [T&W B220; Randell 1979 p.113]iv. Boys, C.V. An Integrating Machine, in The London, Edinburgh, and Dublin Philosophical Magazine, and Journal of Science, fifth series, vol. 11, no. 69, May 1881. 8vo, original printed paper wrappers, upper wrapper detached [T&W B221]v. Hele Shaw, Henry S. (1854-1941). The theory of continuous calculating machines [offprint from:] Philosophical Transactions of the Royal Society - Part II, 1885. London: Trübner and Co for the Royal Society, 1886, folio, numerous illustrations, later wrappers, (bought from Interlibrum, Vaduz, 1993), [T&W H97] vi. Zobel, Johann G., and Müller, J. Beschreibung einer Flächen-Berechnungs und Theilungs-Maschine. Munich: Joseph Lindauer, 1815. 4to, three folding plates, later boards, (bought from Pickering & Chatto, London, 1995), [T&W Z9]

Condition is described in the main body of the catalogue, where appropriate.
"In response to your inquiry, we are pleased to provide you with a general report of the condition of the property described above. Since we are not professional conservators or restorers, we urge you to consult with a restorer or conservator of your choice who will be better able to provide a detailed, professional report. Prospective buyers should inspect each lot to satisfy themselves as to condition and must understand that any statement made by Sotheby's is merely a subjective, qualified opinion. Prospective buyers should also refer to any Important Notices regarding this sale, which are printed in the Sale Catalogue.
NOTWITHSTANDING THIS REPORT OR ANY DISCUSSIONS CONCERNING A LOT, ALL LOTS ARE OFFERED AND SOLD AS IS" IN ACCORDANCE WITH THE CONDITIONS OF BUSINESS PRINTED IN THE SALE CATALOGUE."

The mechanical integraph invented by Abakanowicz was an elaboration of the planimeter. It was "a noteworthy development in the history of calculating instruments, for it represents an early, albeit limited, analog approach to the solution of differential equations" (Tomash & Williams).