Visualising historical change by way of 19th and early 20th century maps and modern age aerial photos, satellite imagery and other raster-based data, is now a freely accessible web browser-based experience and part of the award-winning David Rumsey Historical Map Collection ( www.davidrumsey.com), an Internet site featuring over 6500 high-resolution digital images from one of the largest private map collections in the US.

First of its kind, the new Rumsey Internet GIS mapping service enables web browser interaction and visualisation of 11 different historical maps of San Francisco Bay, from the mid-1800s through the early 1900s, along with digital orthophotos, topographic map sheets, digital elevation models, and satellite imagery from the US Geological Survey. Roads, lakes, parks, and state boundary data are also part of the service. The site will soon include historical maps of New York City, Boston, Los Angeles, Chicago and Washington DC, and ultimately, regions, states and continents. "Placing historical maps on the Internet allows many more people to appreciate them," said Rumsey, President of Cartography Associates (San Francisco, CA). "GIS brings these historical maps into a common, visual language so that we can better understand the context of our history. Integrating geospatial data allows GIS professionals, cartographers and anyone who loves maps and history, to further investigate and visualise historical change."

The new GIS feature for Rumsey's online collection is provided by Maplicity, the Internet GIS and image visualisation software from Telemorphic that provides visitors with robust display and analysis capabilities within a scalable web browser interface.

The collection includes atlases, globes, school geographies, maritime charts, and a variety of separate maps including pocket, wall, children's and manuscript maps. The on-line collection is an expanding cross section of images designed to highlight the depth and breadth of the collection.

source: rumsey@luna-img.com