Whitall, H - ASTRONOMY - INSTRUMENTS: A Movable Planisphere of the Heavens at Every Minute Philadelphia, H Whitall, 1871, as issued. Color star illustrations and constellations. Edition Unknown See Dekker, Globes at Greenwich, pp. 518 - 520. A very good copy. A moveable planisphere appx. 15.5 inches in diameter made of glazed paper card with color figures of the stars and constellations incorporating a printed volvelle. The color printed constellations are revealed as the volvelle is turned through 360 degrees. Both outer and inner disk have printed hours, months, seasons, degrees, altitude scales. The stars and constellations are all named. The verso has three broad columns of printed directions for the use of the instrument. The device was sold to help students and amateur astronomers locate stars and constellations. Whitall manufactured three different types of such ' star finders ' all centered around the latitude of Philadelphia. The constellation guide, offered here, was the most elaborate he produced. He began production in 1862 and changed and improved aspects of the device while advertising them for sale in almanacs and school supply catalogs. The one offered here carries the original 1862 copyright supplemented by the 1871 copyright date. A remarkable artifact.

$2000.

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