[
  {
    "id": "01-integrating-machine",
    "title": "Boys’s integrating machine",
    "source_title": "Scientific American Supplement, No. 288",
    "publisher": "Munn & Co., New York",
    "year": 1881,
    "location": "July 9, 1881; An Integrating Machine, by C. V. Boys",
    "source_url": "https://www.gutenberg.org/files/8391/8391-h/8391-h.htm",
    "image_url": "https://www.gutenberg.org/files/8391/8391-h/images/16a.png",
    "source_file": "source-files/scientific-american-1881-07-09-16a.png",
    "source_sha256": "fe0884b06340eddda60b110ac5de9deb4aaab338023d68c9d833680d99228cac",
    "width_px": 600,
    "height_px": 1042,
    "width_at_300dpi_inches": 2.0,
    "suggested_max_width_2x_css_px": 300,
    "suggested_use": "Oakfield Mathematics; parent company",
    "notes": "The most specific connection to Operator Calculus: an actual mechanical integrator. Keep the original labels.",
    "processing": "Downloaded periodical illustration file; crop where specified; white background converted to transparency. Source was already cleaned by its digitizers.",
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    "rights": "Public domain in the United States",
    "rights_basis": "Published in the United States in 1881. Project Gutenberg explicitly identifies the 1881 issue as public domain in the USA.",
    "retrieved": "2026-09-18"
  },
  {
    "id": "02-steam-wheel",
    "title": "Thomas’s improved steam wheel",
    "source_title": "Scientific American Supplement, No. 288",
    "publisher": "Munn & Co., New York",
    "year": 1881,
    "location": "July 9, 1881; Thomas’s Improved Steam Wheel",
    "source_url": "https://www.gutenberg.org/files/8391/8391-h/8391-h.htm",
    "image_url": "https://www.gutenberg.org/files/8391/8391-h/images/10a.png",
    "source_file": "source-files/scientific-american-1881-07-09-10a.png",
    "source_sha256": "ef27571125ef69bd95f38a7eddb7d9b8cf5f66145b9085dd3e4c94faefc919d7",
    "width_px": 1200,
    "height_px": 960,
    "width_at_300dpi_inches": 4.0,
    "suggested_max_width_2x_css_px": 600,
    "suggested_use": "Oakfield Mathematics; Oakfield Works",
    "notes": "A strong circular cutaway for a service card or section opener.",
    "processing": "Downloaded periodical illustration file; crop where specified; white background converted to transparency. Source was already cleaned by its digitizers.",
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    "rights": "Public domain in the United States",
    "rights_basis": "Published in the United States in 1881. Project Gutenberg explicitly identifies the 1881 issue as public domain in the USA.",
    "retrieved": "2026-09-18"
  },
  {
    "id": "03-refrigerator-elevation",
    "title": "Dry-air refrigerator: elevation",
    "source_title": "Scientific American Supplement, No. 288",
    "publisher": "Munn & Co., New York",
    "year": 1881,
    "location": "July 9, 1881; Dry Air Refrigerating Machine; side elevation",
    "source_url": "https://www.gutenberg.org/files/8391/8391-h/8391-h.htm",
    "image_url": "https://www.gutenberg.org/files/8391/8391-h/images/9d.png",
    "source_file": "source-files/scientific-american-1881-07-09-9d.png",
    "source_sha256": "0bfa037d4ccfff23e4e4ea79d03231bc73c53255ad40048c89cc5a41f558b271",
    "width_px": 1200,
    "height_px": 529,
    "width_at_300dpi_inches": 4.0,
    "suggested_max_width_2x_css_px": 600,
    "suggested_use": "Oakfield Works; parent company",
    "notes": "Recommended lead illustration for the Gazette. A machine illustration, not a locomotive.",
    "processing": "Downloaded periodical illustration file; crop where specified; white background converted to transparency. Source was already cleaned by its digitizers.",
    "page_rotation_ccw": 0,
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    "rights": "Public domain in the United States",
    "rights_basis": "Published in the United States in 1881. Project Gutenberg explicitly identifies the 1881 issue as public domain in the USA.",
    "retrieved": "2026-09-18"
  },
  {
    "id": "04-refrigerator-plan",
    "title": "Dry-air refrigerator: plan",
    "source_title": "Scientific American Supplement, No. 288",
    "publisher": "Munn & Co., New York",
    "year": 1881,
    "location": "July 9, 1881; Dry Air Refrigerating Machine; plan",
    "source_url": "https://www.gutenberg.org/files/8391/8391-h/8391-h.htm",
    "image_url": "https://www.gutenberg.org/files/8391/8391-h/images/9d.png",
    "source_file": "source-files/scientific-american-1881-07-09-9d.png",
    "source_sha256": "0bfa037d4ccfff23e4e4ea79d03231bc73c53255ad40048c89cc5a41f558b271",
    "width_px": 1200,
    "height_px": 697,
    "width_at_300dpi_inches": 4.0,
    "suggested_max_width_2x_css_px": 600,
    "suggested_use": "Oakfield Software",
    "notes": "Connected components offer a useful metaphor for integration. Preserve technical labels.",
    "processing": "Downloaded periodical illustration file; crop where specified; white background converted to transparency. Source was already cleaned by its digitizers.",
    "page_rotation_ccw": 0,
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    "rights": "Public domain in the United States",
    "rights_basis": "Published in the United States in 1881. Project Gutenberg explicitly identifies the 1881 issue as public domain in the USA.",
    "retrieved": "2026-09-18"
  },
  {
    "id": "08-teaching-room",
    "title": "Teaching room with globe",
    "source_title": "Specimen of Printing Types and Ornaments",
    "publisher": "J. Howe & Co., Philadelphia",
    "year": 1830,
    "location": "Scan 270; No. 439",
    "source_url": "https://www.loc.gov/resource/gdcmassbookdig.specimenofprinti00jhow/?sp=270",
    "image_url": "https://tile.loc.gov/image-services/iiif/public:gdcmassbookdig:specimenofprinti00jhow:specimenofprinti00jhow_0270/full/pct:100.0/0/default.jpg",
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    "source_sha256": "eb7da69260844c979b26510c307c58bd4526bb80fe5108c2e234acc2f4c6b7f4",
    "width_px": 1599,
    "height_px": 1090,
    "width_at_300dpi_inches": 5.33,
    "suggested_max_width_2x_css_px": 799,
    "suggested_use": "Applied Infrastructure Conservatory",
    "notes": "A historical teaching vignette; use as an editorial illustration rather than a claim about present-day facilities.",
    "processing": "Crop; quarter-turn orientation where needed; grayscale tonal separation; black ink with transparent background.",
    "page_rotation_ccw": -90,
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    "alpha_white_point": 168.0,
    "alpha_black_point": 40,
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    "rights": "Public domain in the United States",
    "rights_basis": "Published in Philadelphia in 1830; original publication copyright term has expired.",
    "retrieved": "2026-09-18"
  },
  {
    "id": "09-globe-and-trade",
    "title": "Globe, shipping & trade",
    "source_title": "Specimen of Printing Types and Ornaments",
    "publisher": "J. Howe & Co., Philadelphia",
    "year": 1830,
    "location": "Scan 232; No. 274",
    "source_url": "https://www.loc.gov/resource/gdcmassbookdig.specimenofprinti00jhow/?sp=232",
    "image_url": "https://tile.loc.gov/image-services/iiif/public:gdcmassbookdig:specimenofprinti00jhow:specimenofprinti00jhow_0232/full/pct:100.0/0/default.jpg",
    "source_file": "source-pages/howe-1830-scan-232.jpg",
    "source_sha256": "bb13c615d3118179462c378eb431981843333b170877651278b11a01e370101b",
    "width_px": 1024,
    "height_px": 621,
    "width_at_300dpi_inches": 3.41,
    "suggested_max_width_2x_css_px": 512,
    "suggested_use": "Oakfield Intelligence; parent company",
    "notes": "An emblem for global context and commerce.",
    "processing": "Crop; quarter-turn orientation where needed; grayscale tonal separation; black ink with transparent background.",
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    "rights": "Public domain in the United States",
    "rights_basis": "Published in Philadelphia in 1830; original publication copyright term has expired.",
    "retrieved": "2026-09-18"
  },
  {
    "id": "10-spectacles-and-watch",
    "title": "Spectacles & pocket watch",
    "source_title": "Specimen of Printing Types and Ornaments",
    "publisher": "J. Howe & Co., Philadelphia",
    "year": 1830,
    "location": "Scan 186; No. 98",
    "source_url": "https://www.loc.gov/resource/gdcmassbookdig.specimenofprinti00jhow/?sp=186",
    "image_url": "https://tile.loc.gov/image-services/iiif/public:gdcmassbookdig:specimenofprinti00jhow:specimenofprinti00jhow_0186/full/pct:100.0/0/default.jpg",
    "source_file": "source-pages/howe-1830-scan-186.jpg",
    "source_sha256": "1ad3666a91a07cb6c8eba9f1abd198687f9ef77c5112d63ac347e65299264364",
    "width_px": 2004,
    "height_px": 640,
    "width_at_300dpi_inches": 6.68,
    "suggested_max_width_2x_css_px": 1002,
    "suggested_use": "Advisory; Oakfield Intelligence",
    "notes": "Observation and time: useful beside a byline, note, or short announcement.",
    "processing": "Crop; quarter-turn orientation where needed; grayscale tonal separation; black ink with transparent background.",
    "page_rotation_ccw": 0,
    "crop_xyxy_on_rotated_source": [
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    "rights": "Public domain in the United States",
    "rights_basis": "Published in Philadelphia in 1830; original publication copyright term has expired.",
    "retrieved": "2026-09-18"
  },
  {
    "id": "12-pointing-hand-right",
    "title": "Pointing hand: right",
    "source_title": "Specimen of Printing Types and Ornaments",
    "publisher": "J. Howe & Co., Philadelphia",
    "year": 1830,
    "location": "Scan 232; No. 270",
    "source_url": "https://www.loc.gov/resource/gdcmassbookdig.specimenofprinti00jhow/?sp=232",
    "image_url": "https://tile.loc.gov/image-services/iiif/public:gdcmassbookdig:specimenofprinti00jhow:specimenofprinti00jhow_0232/full/pct:100.0/0/default.jpg",
    "source_file": "source-pages/howe-1830-scan-232.jpg",
    "source_sha256": "bb13c615d3118179462c378eb431981843333b170877651278b11a01e370101b",
    "width_px": 1372,
    "height_px": 599,
    "width_at_300dpi_inches": 4.57,
    "suggested_max_width_2x_css_px": 686,
    "suggested_use": "Navigation; calls to action",
    "notes": "An original right-pointing cut, not a mirrored reconstruction.",
    "processing": "Crop; quarter-turn orientation where needed; grayscale tonal separation; black ink with transparent background.",
    "page_rotation_ccw": -90,
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    "alpha_black_point": 40,
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    "rights": "Public domain in the United States",
    "rights_basis": "Published in Philadelphia in 1830; original publication copyright term has expired.",
    "retrieved": "2026-09-18"
  },
  {
    "id": "14-floral-divider",
    "title": "Floral divider",
    "source_title": "Specimen of Printing Types and Ornaments",
    "publisher": "J. Howe & Co., Philadelphia",
    "year": 1830,
    "location": "Scan 204; No. 162",
    "source_url": "https://www.loc.gov/resource/gdcmassbookdig.specimenofprinti00jhow/?sp=204",
    "image_url": "https://tile.loc.gov/image-services/iiif/public:gdcmassbookdig:specimenofprinti00jhow:specimenofprinti00jhow_0204/full/pct:100.0/0/default.jpg",
    "source_file": "source-pages/howe-1830-scan-204.jpg",
    "source_sha256": "39708ada825d78d64a3c56c92e2cefbdceab61868ad51e9789071019991023b4",
    "width_px": 2725,
    "height_px": 283,
    "width_at_300dpi_inches": 9.08,
    "suggested_max_width_2x_css_px": 1362,
    "suggested_use": "Masthead; section dividers",
    "notes": "Best shared ornament for the umbrella brand.",
    "processing": "Crop; quarter-turn orientation where needed; grayscale tonal separation; black ink with transparent background.",
    "page_rotation_ccw": 0,
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    "alpha_black_point": 40,
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    "rights": "Public domain in the United States",
    "rights_basis": "Published in Philadelphia in 1830; original publication copyright term has expired.",
    "retrieved": "2026-09-18"
  },
  {
    "id": "16-rosette-divider",
    "title": "Rosette divider",
    "source_title": "Specimen of Printing Types and Ornaments",
    "publisher": "J. Howe & Co., Philadelphia",
    "year": 1830,
    "location": "Scan 246; No. 325",
    "source_url": "https://www.loc.gov/resource/gdcmassbookdig.specimenofprinti00jhow/?sp=246",
    "image_url": "https://tile.loc.gov/image-services/iiif/public:gdcmassbookdig:specimenofprinti00jhow:specimenofprinti00jhow_0246/full/pct:100.0/0/default.jpg",
    "source_file": "source-pages/howe-1830-scan-246.jpg",
    "source_sha256": "2286f5e252e11af8faea0dc610784be5dca8bb447898ddbc87e4b00765f4121f",
    "width_px": 2277,
    "height_px": 179,
    "width_at_300dpi_inches": 7.59,
    "suggested_max_width_2x_css_px": 1138,
    "suggested_use": "Article headings; presentation footers",
    "notes": "Long rule with a circular center.",
    "processing": "Crop; quarter-turn orientation where needed; grayscale tonal separation; black ink with transparent background.",
    "page_rotation_ccw": -90,
    "crop_xyxy_on_rotated_source": [
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    "rights": "Public domain in the United States",
    "rights_basis": "Published in Philadelphia in 1830; original publication copyright term has expired.",
    "retrieved": "2026-09-18"
  },
  {
    "id": "18-geometric-frame",
    "title": "Geometric frame",
    "source_title": "Specimen of Printing Types and Ornaments",
    "publisher": "J. Howe & Co., Philadelphia",
    "year": 1830,
    "location": "Scan 246; No. 328",
    "source_url": "https://www.loc.gov/resource/gdcmassbookdig.specimenofprinti00jhow/?sp=246",
    "image_url": "https://tile.loc.gov/image-services/iiif/public:gdcmassbookdig:specimenofprinti00jhow:specimenofprinti00jhow_0246/full/pct:100.0/0/default.jpg",
    "source_file": "source-pages/howe-1830-scan-246.jpg",
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    "width_px": 1854,
    "height_px": 1249,
    "width_at_300dpi_inches": 6.18,
    "suggested_max_width_2x_css_px": 927,
    "suggested_use": "Oakfield Press; service notices",
    "notes": "Original frame preserved. Catalog price and number removed from the blank interior in the transparent version.",
    "processing": "Crop; quarter-turn orientation where needed; grayscale tonal separation; black ink with transparent background. Blank interior cleared, including the catalog number and price; original crop retained.",
    "page_rotation_ccw": -90,
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    "interior_clear_rect_reference_1600px": [
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    "rights": "Public domain in the United States",
    "rights_basis": "Published in Philadelphia in 1830; original publication copyright term has expired.",
    "retrieved": "2026-09-18"
  },
  {
    "id": "19-palmette-frame",
    "title": "Palmette frame",
    "source_title": "Specimen of Printing Types and Ornaments",
    "publisher": "J. Howe & Co., Philadelphia",
    "year": 1830,
    "location": "Scan 246; No. 329",
    "source_url": "https://www.loc.gov/resource/gdcmassbookdig.specimenofprinti00jhow/?sp=246",
    "image_url": "https://tile.loc.gov/image-services/iiif/public:gdcmassbookdig:specimenofprinti00jhow:specimenofprinti00jhow_0246/full/pct:100.0/0/default.jpg",
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    "width_px": 1845,
    "height_px": 1293,
    "width_at_300dpi_inches": 6.15,
    "suggested_max_width_2x_css_px": 922,
    "suggested_use": "Featured service; presentation title",
    "notes": "Use sparingly for larger announcements. Interior catalog text removed in the transparent version.",
    "processing": "Crop; quarter-turn orientation where needed; grayscale tonal separation; black ink with transparent background. Blank interior cleared, including the catalog number and price; original crop retained.",
    "page_rotation_ccw": -90,
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    "rights": "Public domain in the United States",
    "rights_basis": "Published in Philadelphia in 1830; original publication copyright term has expired.",
    "retrieved": "2026-09-18"
  },
  {
    "id": "06-acoustic-instrument",
    "title": "Bell’s modified microphone",
    "source_title": "Scientific American Supplement, No. 288",
    "publisher": "Munn & Co., New York",
    "year": 1881,
    "location": "July 9, 1881; Upon a Modification of Wheatstone’s Microphone and Its Applicability to Radiophonic Researches, by Alexander Graham Bell; Fig. 2",
    "source_url": "https://www.gutenberg.org/files/8391/8391-h/8391-h.htm",
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    "source_sha256": "cde95ea3086849e0c8a403be3c067d52348f7ea95dfb599e9b278d212f506b35",
    "width_px": 324,
    "height_px": 400,
    "width_at_300dpi_inches": 1.08,
    "suggested_max_width_2x_css_px": 162,
    "suggested_use": "Magnetic Reference",
    "notes": "An acoustic research instrument, not a magnetic recorder. Small supporting cut: 324 pixels wide.",
    "processing": "Downloaded periodical illustration file; crop where specified; white background converted to transparency. Source was already cleaned by its digitizers.",
    "page_rotation_ccw": 0,
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    "rights": "Public domain in the United States",
    "rights_basis": "Published in the United States in 1881. Project Gutenberg explicitly identifies the 1881 issue as public domain in the USA.",
    "retrieved": "2026-09-18"
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]