This past weekend I attended a Guild of Bookworkers, Delaware Chapter workshop taught by Pamela Spitzmueller. Pam is the first James W. Needham Chief Conservator for Special Collections in the University Library and the College Library at Harvard University. The workshop was to inform us about considerations that must be taken into account with folded items within an atlas structure. This workshop was important for us, not only because we have so many maps in book as well as atlases, but also for all of the genealogical charts!
Each participant in the GBW workshop completed a 3x5 sample book of different kinds of folds as well as several models of other books.
The sample book:
The squashed scroll:
The side cut fold:
side cut fold again:
map which unfolds completely outside of the book allowing for the rest of the book to be read with the map unfolded for reference:
and the Chinese Road Atlas:
The workshop was great for bringing awareness to what can go wrong when maps are folded into books. When I got back on Monday I was excited to pull some of our older atlases and take a look at them with a fresh eye.
One of my favorites is this "Atlas" presented to John Hancock, Esq. Yes, THE John Hancock.
This is a large volume with maps showing the coastline from Maine to Florida. It gives information about how to avoid the gulf stream as well as some of the more treacherous shoals. The book is made up of the maps which have been printed on several different sizes of paper. Some of them fold out, some do not. A label on the front says 1780.
Next I looked at "Europe Divided after D'Annville" 1795. This atlas had a lot of good packing and compensating material. Much thought went into the construction by the binder. You can see all of the compensating material in this spine shot. This was used to create enough room in the spine so that the folded maps - which are thicker than a single sheet of paper - wouldn't make the book splay open. (the book was also "repaired" at some point and you can see the new material under the spine)
Inside the book are some fantastic engravings. This map of Minorca is beautifully designed. It includes a larger map in the upper left, a view of the harbor in the upper right, the actual island in the middle and two elevations of different cities in the bottom right and left. This map is printed on one sheet of paper which is folded in half and glued to a tab. The tab is what is sewn into the spine and binding of the book.
This large engraving of the southern half of Ireland has suffered from use in this perfect example of when things go wrong. Here is the image before it's opened:
after opening: between Kerry and Waterford you should be able to read Cork. 
However, that area shows typical damage of a folded map tipped in too closely to the spine.
And finally another atlas, the Altas Geographicus Maior, 1759-1762, is much thicker than either of the previous books. It contains maps which fold out in various directions. Including this one of the "Filipines".
It is possible to see where the folding has damaged the book in both of these images.
This page also has a beautiful little compass rose. Here's a detail for you:
This last book had another especially nice little image on the title page:
