This section is from the book "Spons' Mechanics' Own Book: A Manual For Handicraftsmen And Amateurs", by Edward Spon. Also available from Amazon: Spons' Mechanics' Own Book.
Fig. 696 illustrates the construction of a folding portable bookcase, which may be carved and ornamented to any degree. The 2 ends a are 4 ft. long over all and 1 ft. wide, either of plain board, or panelled as shown; uprights b, 3 1/2 in. wide and 1 in. thick, are fastened to the front, and similar ones c, 2 1/4 in. by 3/4 in. to the back. Cross pieces are dovetailed into the bottoms, of the same width as the uprights, and similar ones are mortised into the tops, thus forming shallow boxes. The top board of the bookcase is hinged at one end underneath one cross piece, and folds down parallel to that end piece, allowing sufficient space behind it to contain one of the shelves. The bottom board forming the lowest shelf is hinged to the cross piece at the bottom of the other end piece, with sufficient space to admit the second shelf behind it. As the bookcase is 3 ft. 6 in. wide, the back may consist of 4 boards hinged together as at d, and folding neatly up. The space e will hold the ornamental baluster railing fitted to the top, and which is held in place when the bookcase is up by shallow tenons mortised into the uprights b. The shelves are held up by shallow tenons.
The back is made of 5/8-in. wood; the ends and shelves are 3/4 in.