This layer is a georeferenced raster image of the United States Geological Survey sheet map entitled: Philadelphia County, Pennsylvania, produced by the United States Geological Survey ; Commonwealth of Pennsylvania, Department of Environmental Resources, Topographic and Geologic Survey. It was published in 1983. Scale 1:50,000. Compiled from USGS 1:24,000-scale topographic maps. Planimetry revised from aerial photographs taken in 1981 and other source data. Revised information not field checked. Map edited 1982.
The image inside the map neatline is georeferenced to the surface of the earth and fit to the Pennsylvania South State Plane Coordinate System NAD27 (in Feet) (Fipszone 3702). All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map.
USGS maps are typical topographic maps portraying both natural and manmade features. They show and name works of nature, such as mountains, valleys, lakes, rivers, vegetation, etc. They also identify the principal works of humans, such as roads, railroads, boundaries, transmission lines, major buildings, etc. Relief is shown with standard contour intervals of 20 feet and spot heights.
Please pay close attention to map collar information on projections, spheroid, sources, dates, and keys to grid numbering and other numbers which appear inside the neatline. Includes notes, index to 1:24,000-scale maps, and location map.
This layer is part of a selection of digitally scanned and georeferenced historic maps from The Harvard Map Collection as part of the Imaging the Urban Environment project. Maps selected for this project represent major urban areas and cities of the world, at various time periods. These maps typically portray both natural and manmade features at a large scale. The selection represents a range of regions, originators, ground condition dates, scales, and purposes.