Record Group 156 - Records of the Office of the Chief of Ordnance
Number of Textual Scans online
The progress bar provides an estimate of the percentage of textual pages in this Record Group that are available online. Some Record Groups contain only one format while others include multiple formats.
About the Record Group Explorer Numbers
The Record Group Explorer data visualization is based on a count of the scans of textual pages available through the National Archives Catalog and an estimate of the total number of textual pages currently in NARA's holdings. Numbers will be updated monthly to reflect new additions to the Catalog and future iterations of the Explorer will provide additional data on records types other than textual records.
How Record Group Explorer Numbers are Calculated
The number of scans online uses file counts accessed via the National Archives Catalog API.
The estimated total pages in each Record Group is calculated by taking the volume of textual records (in cubic feet) and multiplying by an average of 2,500 pages of records per cubic foot. The 2,500 page average coming from historical capacity estimates for the standard (Hollinger) box used to preserve and store archival documents.
The percent of scanned textual pages online equals scans online / estimated total pages
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In the meantime, explore descriptions of our records. These records, though not yet digitized, are available at National Archives locations.