[6] On the instruments used at Mannheim see Gerland and Traumüller, op. cit. footnote 1, p. 349ff. The Princeton physicist Arnold Guyot prepared a set of instructions for observers that was published in Tenth Annual Report ... of the Smithsonian Institution, 1856, p. 215ff. It appears from the Annual Report of the British Association for the Advance of Science in the 1830's that the instruments used in England were nearly the same as those later adopted by the Smithsonian, although British observatories were beginning to experiment with the self-registering anemometer at that time. A typical set of the Smithsonian instruments is shown in figure 1.
[7] H. Alan Lloyd, "Horology and Meteorology," Journal Suisse d'Horlogerie, November-December, 1953, nos. 11, 12, p. 372, fig. 1.
[8] R. T. Gunther, Early Science in Oxford, vol. 6, The Life and Work of Robert Hooke, pt. 1, Oxford, 1930, p. 196. In 1670, Hooke's proposed clock was referred to as "such a one, as Dr. Wren had formerly contrived" (Gunther, p. 365).
[9] William Derham, Philosophical Experiments and Observations of ... Dr. Robert Hooke, London, 1726, pp. 41-42 (reprinted in Gunther, op. cit. footnote 8, vol. 7, pp. 519-520). This description, dated December 5, 1678, predates the Royal Society's request for a description (Gunther, op. cit. footnote 8, p. 656) by four months, but the Society no longer has any description of the clock. As to the actual completion of the clock, the president of the Society visited "Mr. Hooke's turret" to see it in January of 1678/79 but it was not reported "ready to be shown" until the following May (Gunther, pp. 506, 518).
[10] Wren's clock and its wind vane and anemometer, thermometer, barometer, and rain gauge are described by T. Sprat, The History of the Royal Society..., London, 1667, pp. 312-313. On the balance-barometer, see also footnote 28, below, and figure 4.
[11] Since the above was written, additional information on this clock has been published by H. E. Hoff and L. A. Geddes, "Graphic Recording before Carl Ludwig: An Historical Summary," Archives Internationales d'Histoire des Sciences, 1959, vol. 12, pp. 1-25. Hoff and Geddes call attention to a report on the clock by Monconys, who saw the instrument in 1663 and published a brief description and crude sketch (Balthasar Monconys, Les Voyages de Balthasar de Monconys; Documents pour l'Histoire de la Science, avec une Introduction par M. Charles Henry, Paris, 1887). Monconys says that the thermometer "causes a tablet to rise and fall while a pencil bears against it." The instrument shown in his sketch resembles a Galilean thermoscope.
[12] Hooke's "oat-beard hygrometer" was described in 1667, but Torricelli seems to have invented the same thing in 1646, according to E. Gerland, "Historical Sketch of Instrumental Meteorology," in "Report of the International Meteorological Congress Held at Chicago, Ill., August 21-24, 1893," O. L. Fassig, ed., U.S. Weather Bureau Bulletin No. 11, pt. 3, 1896, pp. 687-699.
[13] But a Dutch patent was awarded to one William Douglas in 1627 for the determination of wind pressure (G. Doorman, Patents for Inventions in the Netherlands during the 16th, 17th and 18th Centuries, The Hague, 1942, p. 127), and Leonardo da Vinci left a sketch of both a wind pressure meter and a hygrometer (Codex Atlanticus, 249 va and 8 vb).
[14] Gunther, op. cit. (footnote 8), pp. 433, 502.
[15] Battista della Valle, Vallo Libro Continente Appertiniente ad Capitanii, Retenere and Fortificare una Citta..., Venetia, 1523 (reported under the date 1524 in G. H. Baillie, Clocks and Watches, an Historical Bibliography, London, 1951).