Fun in cataloging, or, the mysterious 12mo

On occasion, interesting and unusual aspects of books, manuscripts, and prints catch the attention of the cataloger at work on them.1 The office of the Cataloging and Metadata Department (located on Deck A right below the Paster Reading Room) is an open area with a large table in the center, which makes it really easy to show each other the cool stuff we come across. Something interesting, unusual, and cool crossed my desk recently, and it seems a shame not to share it with a wider community.

title page of John Newton's Tabulae mathematicae

title page of John Newton’s Tabulae mathematicae

John Newton’s Tabulae Mathematicae, or, Tables of the Naturall Sines, Tangents and Secants, published in 1654, offers up exactly what the title promises: hundreds and hundreds of pages of dense numbers in tabular form. Tucked in among its 452 unnumbered pages is a folded leaf containing (wait for it … ) a table. So far, nothing unusual.

Now we’re getting to the fun part. When the folded leaf is unfolded, we see a lot of wasted space, in stark contrast to the compact printing everywhere else. 

a table at the ready (fol. Q11r)

a table at the ready (fol. Q11r)

The table’s title is at the top left, above the blank space. Instructions to the binder are printed below the blank space and running perpendicular at the fore-edge. The binder of this volume ignored the instruction to cut along the black line—else we wouldn’t be reading it—but otherwise followed orders. The purpose of this mostly blank half page? To push the content out, permitting the reader to consult two tables simultaneously.

the extended table, as seen from fol. Q2v-Q3r

the extended table, as seen from fol. Q2v-Q3r

One anomaly mars the book’s otherwise regular physical structure. The text consists of 19 whole sheets of paper that, when printed on both sides and folded, yields 12 leaves each. These sections, or gatherings, are signed sequentially from A-T, and each has 12 leaves except for gathering Q, the one that contains our folded sheet.2 Q goes only to 10, followed directly by the folded leaf.

There are two pieces of helpful information for understanding what this anomaly might mean. First: as you can see from the diagram below, in a duodecimo the last four leaves of the gathering are printed as a strip that is then cut from the rest of the sheet before it is folded into its gathering:

imposition for a 12mo (taken from Gaskell, A New Introduction to Bibliography)

chart showing imposition for a 12mo (from Gaskell, A New Introduction to Bibliography)

And the second tidbit of useful information: folded leaves were typically printed separately—larger than the leaves of text, they couldn’t conveniently be set and printed together—and inserted by the binder into the correct place.

As you can see, a 12mo might easily have a gathering of 8 leaves instead of 12, but 10? What’s happened to the remaining 2 leaves? If you look again at the unfolded leaf, you’ll see that it is roughly twice the width of a regular leaf. The plot is thickening nicely: gathering Q alone has 10 leaves, and just where we would expect the 11th and 12th leaves of Q, we instead get a folded leaf that corresponds to the width of two leaves side-by-side. I postulate that, in contrast to how folded leaves were typically handled, this one was printed on the same sheet with the rest of Q.

No one else I showed this book to has seen anything like it, either the only usable part of a folded leaf extending beyond textblock, or evidence of folded leaves imposed together with the rest of the text. We would love to hear more about either phenomenon!

  1. One such item was written up by Sarah Werner last December in “‘Tis the season for almanacs.” []
  2. For more on signature marks, see Sarah’s “Deciphering signature marks“. []

Author: Deborah J. Leslie

DEBORAH J. LESLIE is Senior English Rare Book Cataloger at the Folger Shakespeare Library. She is active in the Rare Books and Manuscripts Section of the American Library Association, and teaches introductory and advanced rare book cataloging at Rare Book School. She is passionate about the letter W.

3 Comments

  1. Nifty! This kind of plate is known as a “throwout” plate, and is nicely described by Roger Gaskell in “Printing house and Engraving Shop,” _The Book Collector_, vol. 53, no. 2 (Summer 2004), page 213-251. He writes, “The familiar problem of reading the text of a book while referring to an illustration was commonly solved in the seventeenth and eighteenth centuries by binding the plates as throwouts. Throwout plates are attached to the book in such a way that they can be opened out with the image thrown clear of the text block, so that any page can be read while looking at the illustration.”

    Sometimes throwouts were planned by the printer/publisher, like this example. In other cases, they’re copy-specific: the binder would add a blank leaf, then paste the plate face-down along the fore-edge.

  2. What are the conjugacies? In other words, how does the imposition of Q differ from the Gaskell diagrams? Are Q1 and 2 singletons, or might the foldout table have been printed as Q11-12 and remained attached to either Q1 or Q2, with the sewing after Q6 as in a normal gathering of 12? (Is there anything on the reverse of the foldout table, or is it blank?)

    • That’s a good question. Deborah is out of town, but I’ll pop down into the Reading Room as soon as I have a chance and see what I can find out.

%d bloggers like this: