American Memory:  Technical summary

Architectural Drawings Selected from the HABS/HAER Collection

HABS/HAER 
images

URL for preview: http://lcweb2.loc.gov/ammem/hhhtml/habshome.html


Collection Overview

Description
Group of measured documentation drawings of architectural and engineering structures, including a cathedral, a barn, a windmill, a schooner, Thomas Jefferson's Monticello, and other sites. This small group of drawings presages the larger collection to be placed online during the next three years, when these drawings and many others will be joined with photographs and written documentation to present information about 30,000 structures.
Source collection
Historic American Buildings Survey and Historic American Engineering Record Collections, Prints and Photographs Division. Drawings (and other materials) produced by the HABS and HAER projects are transferred by the National Park Service to the Library of Congress to provide permanent storage and public access.
Technical features
Large, detailed measured drawings, documenting a wide range of structures. Original drawing sizes include "B" (18x24 inches), "D" (24x36 inches), and "E" (34x44 inches).
Original material formats
Number of original items
Selected set: 20 sites (236 drawings)
Status of collection
Preview available online. Descriptive database (but no digital content) for full collection available through Prints & Photographs Online Catalog. Descriptive database will be made available through American Memory later in 1998. Digital content will be added in stages.
Public access
The Library is not aware of any restrictions on these materials. See notes on rights and restrictions provided by the Library to users of the collection preview..

Aids to intellectual access

Type & granularity
Database of descriptive records. Each record describes a site or structure represented by a number of drawings, photographs, and data pages. Sample display from preview.
Linking to digital reproductions
Descriptive record contains identifier used as directory name for "metaobject" containing all materials related to a site. This directory has separate subdirectories for photographs (/photo/), drawings (/sheet/), and images of data pages (/data/). Sample subdirectory for drawings. Last character of filename indicates image type.

Digital reproductions

Total file-space for digital reproductions: 165 Mbytes (estimate)

Drawings Archival image Service images
Marker Filename ends "a" Not yet available
Formats TIFF (ITU Group IV compression)
D size - stripped
B & E sizes - tiled
Tonal resolution 1 bit
Spatial resolution (approx) 400 dpi
Quantity (approx) 236 drawings
File size .6-1 Mbytes
Sample Sample archival Sample service
(test)

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