The word Planisphere (Latin planisphaerium) was originally used in the second century by Claudius Ptolemy to describe the representation of a spherical Earth by a map drawn in the plane. This usage continued into the Renaissance: for example Gerardus Mercator described his 1569 world map as a Planisphere. The word describes the representation of the star-filled celestial sphere on the plane. The first star chart to have the name "Planisphere" was made in 1624 by Jacob Bartsch. Bartsch was the son-in-law of Johannes Kepler, discoverer of Kepler's laws of planetary motionA significant item of celestial mapping used by marine navigators This particular item was made and used in the first quarter to half of the 20th century.Planisphere consists of a circular star chart attached at its centre to an opaque circular overlay that has a clear elliptical window or hole so that only a portion of the sky map will be visible in the window or hole area at any given time. The chart and overlay are mounted so that they are free to rotate about a common pivot point at their centers. The star chart contains the brightest stars, constellations and (possibly) deep-sky objects visible from a particular latitude on Earth. The night sky that one sees from the Earth depends on whether the observer is in the northern or southern hemispheres and the latitude. A Planisphere window is designed for a particular latitude and will be accurate enough for a certain band either side of that. Planisphere makers will usually offer them in a number of versions for different latitudes. Planispheres only show the stars visible from the observer's latitude; stars below the horizon are not included. A complete twenty-four-hour time cycle is marked on the rim of the overlay. A full twelve months of calendar dates are marked on the rim of the star chart. The window is marked to show the direction of the eastern and western horizons. The disc and overlay are adjusted so that the observer's local time of day on the overlay corresponds to that day's date on the star chart disc. The portion of the star chart visible in the window then represents (with a distortion because it is a flat surface representing a spherical volume) the distribution of stars in the sky at that moment for the Planispheres designed location. Users hold the Planisphere above their head with the eastern and western horizons correctly aligned to match the chart to actual star positions. "Sold by J DONNE & SON, Booksellers & Stationers, 349 Post Office Place Melbourne 349. Admiralty Chart Agents" and " Made in Germany for George Philip & Son Ltd" England . Signature "Capt E. B. ?..id, 22 Baund St"flagstaff hill, warrnambool, shipwrecked-coast, flagstaff-hill, flagstaff-hill-maritime-museum, maritime-museum, shipwreck-coast, flagstaff-hill-maritime-village, star map, marine navigation, maps, george philip & sons

Defence Instruction (Air Force) AAP 7832.002-4-3

RAAF

This map from the mid-18th century doesn't include the finer details of land and sea masses that we know today. The map was produced by German cartographer and publisher, Johann Baptist Homann (1663-1724) and published in 1746, after his death. Earlier versions were published, such as 1707 and 1716. The date can be calculated from the Roman numerals on the top left text area. This print of a map is significant for its connection with early world explorers. A comparison of maps over the centuries shows the progression of navigational technology, the countries who claimed the land they explored. The naming of even some Australian locations shows who had already made their mark on Australia in the early 18th century. The print shows the fine details included by the cartographer and the beauty included that makes it attractive and interesting even today. The map is also significant for its connection with German cartographer, Johann Baptist Homann, whose Homann publishing company was renewed in Germany for producing high quality maps and atlases. Map behind glass in dark brown wooden frame on beige paper. The Coloured hand drawn line drawings show different hemispheres of the known world in the mid-18th century. Beautifully drawn figures and decorative embellishments enhance the map. The text on the top right has an explanation of the Figures I, II, III, and IV. This print of the 1746 map was produced in England by Leisure Arts Ltd. "PLANIGLOBIL TERRESTRIS" "MDCCXXXXVI" [1746] "MAPPE_MONDE" [Medieval Map of the World] "LEISURE ARTS LTD" "Printed in England"flagstaff hill, warrnambool, flagstaff hill maritime museum, flagstaff hill maritime village, flagstaff hill maritime museum and village, shipwreck coast, world map, french map, 18th century map, leisure arts ltd, cartography, early exploration, cartographer, johann homann (1663-1724), exploration, naviagtion, 1746 planiglobil terrestris