Abstract: A map which may also be a calculating or teaching device includes a flat representation of a planet with one hemisphere on one side and the opposite hemisphere on the opposite side. The hemispheres are projected to the same scale with matching meridian lines, an arbitrary point of interest forms the center of one side and the antipode of the point of interest forms the center of the other side. Scales are provided by which great circle routes may be plotted and measured. The maps are preferably conformed to an azimuth equidistant projection. A variation is disclosed by which the change from night and day is delineated.
Type:
Grant
Filed:
August 7, 1997
Date of Patent:
May 11, 1999
Assignees:
C. Robert Pryor, William E. Pryor
Inventors:
Paul L. Pryor, deceased, C. Robert Pryor, executor