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  1.  15
    Altitude Sundials for Seasonal and Equal Hours.Allan A. Mills - 1996 - Annals of Science 53 (1):75-84.
    Altitude sundials do not require knowledge of the N-S direction to quantify time in terms of either seasonal or equal hours. Methods for determining the corresponding dial patterns are reviewed, and accurately computed data for a latitude of 51°N presented as horizontal, vertical, rectangular, and pillar dials on both timekeeping systems.
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  2.  10
    Canada Balsam.Allan A. Mills - 1991 - Annals of Science 48 (2):173-185.
    Canada balsam is secreted by cells in the bark of the balsam fir Abies balsamea, a conifer widely distributed across Canada and northern U.S.A. Collected by an extraordinarily labour-intensive process, it was initially exported to Europe for use in pharmacy. However, it found a much wider application after Brewster showed that the refractive index of 1·54–1·55 characterizing the vitreous mass remaining after heating the natural product exceeded that of most resins, and therefore closely matched the indices of ‘crown’ and ‘light (...)
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  3.  12
    Early Voltaic Batteries: An Evaluation in Modern Units and Application to the Work of Davy and Faraday.Allan A. Mills - 2003 - Annals of Science 60 (4):373-398.
    Classic voltaic batteries of the silver/zinc and copper/zinc types are the ancestors of today's primary cells, and facilitated the development of many aspects of electrical technology. Nevertheless, they appear never to have been studied and evaluated in a quantitative manner, with results recorded in terms of volts, amps, ohms, and watts. Research of this nature is reported here, and has been conducted for the most part with copper/zinc cells. Log–log graphs of voltage versus load and current, and power versus load, (...)
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  4.  7
    Portable heliostats.Allan A. Mills - 1986 - Annals of Science 43 (4):369-406.
    This paper examines the various types of small, portable heliostat which maintain a beam of sunlight in a constant direction. Used mainly in the second half of the nineteenth century, these instruments were intended for optical demonstrations and the illumination of microscopes and similar apparatus, rather than for astronomical applications. Three basic patterns are distinguished: polar heliostats , biaxial single-mirror heliostats, and coelostats. The theory and geometry of each type is explained, followed by a consideration in chronological order of the (...)
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  5.  8
    Seasonal-Hour Sundials on Vertical and Horizontal Planes, with an Explanation of the Scratch Dial.Allan A. Mills - 1993 - Annals of Science 50 (1):83-93.
    The true form of the seasonal-hour sundial, in both vertical and horizontal planes, has been calculated by spherical trigonometry and displayed with the aid of computer graphics. These grids are presented, and show that the hour lines are in fact shallow curves at sites not on the equator. The curvature becomes very apparent at latitudes exceeding 50°. The true seasonal-hour pattern for a vertical dial at a latitude of 52·6°N is compared with the equiangular scratch dial.
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  6.  14
    The Early History of Insulated Copper Wire.Allan A. Mills - 2004 - Annals of Science 61 (4):453-467.
    In the early 1800s galvanometers could be constructed with the fine gauges of silk-covered copper or silver wires produced for decorative purposes, but when Faraday was making his classic electrical experiments in 1831 he needed a sturdier gauge of copper wire. Bare copper wire was available in many diameters for mechanical applications, but coils for electromagnetic investigations had to be insulated with string and calico. It was soon realized that the cotton-covered springy iron wire then used to hold out the (...)
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  7.  21
    The Lodestone: History, Physics, and Formation.Allan A. Mills - 2004 - Annals of Science 61 (3):273-319.
    The lodestone is an extremely rare form of the mineral magnetite that occurs naturally as a permanent magnet. It therefore attracts metallic iron as well as fragments of ordinary ‘inert’ magnetite. This ‘magic’ property was known to many ancient cultures, and a powerful lodestone has always commanded a high price. By the eleventh century AD the Chinese had discovered that a freely suspended elongated lodestone would tend to set with its long axis approximately north–south, and utilized this property in the (...)
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