Traditional photography had been used for reproducing rare books since at least the late 1850s, but it was expensive and time-consuming. With traditional photography, the camera captures a latent image on light-sensitive transparent film or glass that is then developed and fixed to produce a transparent negative. Next, the transparent negative is exposed onto light-sensitive paper, and then that latent image is developed and fixed to create a positive image on paper. Photostats completely bypass the film stage by exposing the image directly onto a long roll of light-sensitive paper, and greatly speed up the other steps by having them all happen inside the machine while new images continue to be taken.
City of Winnipeg Archives. Photostat Camera and Operator, 1954 (A568 File 15 Item 6)
Basically, the photostat machine is a great big camera with a built-in processing lab attached at the back. The operator puts an original document face-up on a flat bed in front of the camera, and the camera’s lens assembly projects an image of the document onto the roll of sensitized paper. After about ten seconds of exposure, the operator winds the paper forward for the next shot, moving the exposed paper past a sheet trimmer and into the chemical baths that develop and fix the image. Photostats could be air-dried, but to speed up the process, the Folger’s machine included an electric dryer with conveyor belts.
The Folger’s photostat machine was built around an opening in a wall wall so that the paper coming out the back could arrive in a darkroom (the “Laboratory” in the architectural plan). However, because the rooms had been built for a smaller machine, space was tight, and the plumbing and electrical outlets were in the wrong places. With plenty of help from the Washington office of the Photostat Corporation (which also preferred that the library purchase the $2,190 No. 4 system, not the No. 2) the architects managed to make it work in the existing space, seen below in a detail from the original plans for the Folger’s second floor.
Detail of Photostat Room and Laboratory from Sheet 5 (“Second Floor”) of Folger Shakespeare Library plans, Nov. 4, 1929.
The importance of the photostat room was noted in press and publicity when the library opened in 1932. For instance, a gushing description of the Tudor-style Reading Room in a supplement to The Washington Post ends with “[Mr. Folger’s] capacity to sympathize with the modern scholar’s requirements is exemplified by the fact that a properly equipped photostatic laboratory is hidden behind the paneling.”
Because photostats are direct images, the blacks and whites are reversed, like a film negative in traditional photography. The Folger copy of the 1656 translation of Jean-Nicolas de Parival’s History of this iron age (Hamnet record) includes an example:
Damaged leaf followed by a negative photostat of the same leaf from another copy of the book. Notice that the photostat itself has deteriorated: the “silver mirroring” or “silvering” causing reflection in parts of the dark areas is the result of silver oxidation in the light-sensitive emulsion.
As you can see from the photo, the last leaf of the volume has major losses to the text. Photostats of the same pages from an undamaged copy were inserted when the book was conserved and rebound.
If you only need one copy of a page, and don’t already have a photostat of that page on file, a negative photostat is the cheapest way to go: you make a photostat of the page, and you’re done. But if you make a photostat, then make a photostat of that photostat, the negative/positive reverses again, and you get black letters on a white page. But you’ve just spent twice as much on supplies. For example, leaves b2 and b3 are missing from the introduction to the Folger copy of the 1688 edition of The lives of the popes (Hamnet record), so positive photostats of from Harvard’s copy are provided in a separate envelope:
Two missing leaves provided separately as positive photostats from another copy.
Because positive photostats are second-generation copies, the letters are usually a bit fuzzier than in negative photostats, but they’re much easier on the eye to read.
The Bibliographical Society of America devoted their 1921 annual meeting to the topic of photostats and photographic reproductions in bibliographic research. Reading The Papers of the Bibliographical Society of America, volume 15, part 1, you could substitute “digital image” for “photostat” and almost invariably have something that sounds like it was written in the past ten or fifteen years.
Just as people today dream of digitizing at least one copy of every book ever, people in 1921 dreamed of a coordinated system to make a negative photostat of every book. George P. Winship, librarian of the Widener Collection at Harvard, wrote about how “this whole problem of photostatting for libraries can be handled satisfactorily” by means of a “grand central storehouse, centrally located and big enough to keep all the negatives that have been or are to be made, with facilities for making prints promptly whenever a student anywhere wants them for use.” To be fair, he was only talking about every book and future book in American libraries, not the whole world, but that’s still a lot of books.
Henrietta C. Bartlett, who used photostats extensively when comparing Shakespeare quartos, included a warning about their limitations in her praise:
The only serious “out” is that one cannot tell anything about the paper and therefore cannot tell whether the leaf is genuine or spurious, whether it originally belonged there or was from another copy or edition, whether some leaves have been canceled or not. … The photostat is better, I believe, than any other method of reproduction, but it should not be considered of equal value to the student with the original.
During the discussion period following Chester March Cate’s presentation “The Photostat and the Huntington Library,” attendees “spoke of the possibility of altering or faking photostat copies” and worried about “the permanency of reproduced copies.” H. H. B. Meyer, Chief Bibliographer at the Library of Congress, supported the plan to create a central depository of photostatic negatives, and agreed that the Library of Congress would be the best place for it, but had to allow as how it was impossible at the moment because the library “was unable to do its own work properly, owing to lack of resources.” Does any of this sound familiar?
Only one part of the 1921 discussion struck me as unfamiliar, and I’m very glad for that. Chester March Cate wrote that pointing out an error in another library’s catalog produced “so spirited a reply” from the librarian that he didn’t want to ask the same librarian to double-check the imprint of another book, which he suspected had been mis-transcribed in the catalog. “He, however, readily acceded to our request for a photostat; and by that means we were able to to confirm our suspicions of his error and at the same time to preserve cordial relations between the two institutions. If you suspect something in the Folger Shakespeare Library’s catalog is incorrect, please DO let us know by emailing HamnetHelp@folger.edu. Our reply will also be spirited, but the energy will be an enthusiastic “Thank you!”