From a collection of bookmarks found in Berkeley California. Probably from about 1910. J.H. Furst of Baltimore is still in business as a printer having 'opened their doors' in 1904.
It is possible their books were subject to cracking especially when new but the instructions seem slightly fussy by today's standards although any violence towards a book is still, of course, abhorrent.
HOW TO OPEN
A NEW BOOK
STAND the book, back downward, on a table or smooth surface. Press the front cover down until it touches the table, then the back cover, holding the leaves in one hand while you open a few of the leaves at the back, then at the front, alternately pressing them down gently until you reach the center of the volume. This should be done two or three times. Never open a book violently nor bend back the covers. It is likely not only to break the back but also to loosen the leaves.
HOW TO CARE
FOR A BOOK
THE covers of a new binding are likely to warp while seasoning. This warping may be prevented by placing the book under weight while it is not in use, or wedging tightly between other books on the shelf.
J.H. FURST COMPANY