Each photo is cropped to 3:2 and resized to 640/800/960/1200px widths,
in AVIF, WebP and JPEG (photo-NN-WIDTH.EXT).

photo-01-*: "The Long Room, Trinity College Dublin" by Diliff
  Licence: CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0
  Source:  https://commons.wikimedia.org/wiki/File:Long_Room_Interior,_Trinity_College_Dublin,_Ireland_-_Diliff.jpg

photo-02-*: "George Peabody Library, Baltimore" by Matthew Petroff
  Licence: CC BY-SA 3.0 https://creativecommons.org/licenses/by-sa/3.0
  Source:  https://commons.wikimedia.org/wiki/File:George-peabody-library.jpg

photo-03-*: "Divinity School, Bodleian Library, Oxford" by Diliff
  Licence: CC BY-SA 3.0 https://creativecommons.org/licenses/by-sa/3.0
  Source:  https://commons.wikimedia.org/wiki/File:Divinity_School_Interior_3,_Bodleian_Library,_Oxford,_UK_-_Diliff.jpg

photo-04-*: "Under the magnifying glass" by Heptagon
  Licence: Public domain
  Source:  https://commons.wikimedia.org/wiki/File:Magnifying_glass2.jpg

photo-05-*: "Duchess Anna Amalia Library, Weimar" by Steffen Schmitz
  Licence: CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0
  Source:  https://commons.wikimedia.org/wiki/File:Weimar,_Herzogin_Anna_Amalia_Bibliothek,_2019-09_CN-03.jpg

photo-06-*: "Heyne Reading Room, Göttingen" by Frank Schulenburg
  Licence: CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0
  Source:  https://commons.wikimedia.org/wiki/File:Blick_in_den_Heyne-Lesesaal_der_Nieders%C3%A4chsischen_Staats-_und_Universit%C3%A4tsbibliothek,_September_2022.jpg

photo-07-*: "The study, Abbotsford House" by Michael D Beckwith
  Licence: CC0 http://creativecommons.org/publicdomain/zero/1.0/deed.en
  Source:  https://commons.wikimedia.org/wiki/File:Abbotsford_House_Study_Room.jpg

photo-08-*: "The Vinland Map" by Yale University Press
  Licence: Public domain
  Source:  https://commons.wikimedia.org/wiki/File:Vinland_Map_HiRes.jpg

photo-09-*: "Reading room, Bibliothèque historique de la Ville de Paris" by BHVP
  Licence: CC BY-SA 3.0 https://creativecommons.org/licenses/by-sa/3.0
  Source:  https://commons.wikimedia.org/wiki/File:Salle_de_lecture_vue_d%27ensemble.jpg

photo-10-*: "Upper Lusatian Library of Sciences, Görlitz" by Ralf Roletschek
  Licence: CC BY 3.0 https://creativecommons.org/licenses/by/3.0
  Source:  https://commons.wikimedia.org/wiki/File:13-11-02-olb-by-RalfR-03.jpg

photo-11-*: "Humanist Library of Sélestat" by Photo Claude TRUONG-NGOC
  Licence: CC BY-SA 3.0 https://creativecommons.org/licenses/by-sa/3.0
  Source:  https://commons.wikimedia.org/wiki/File:Biblioth%C3%A8que_humaniste_de_S%C3%A9lestat_21_janvier_2014-97.jpg

photo-12-*: "Turgot map of Paris, 1734–1739" by Louis Bretez / Claude Lucas
  Licence: Public domain
  Source:  https://commons.wikimedia.org/wiki/File:Turgot_map_of_Paris,_sheet_10_-_Norman_B._Leventhal_Map_Center.jpg