4. Making the Book
The exhibition's selection of prints were framed by the Museum for display. However, the series of printed images comprising Ferdinand Verbiest's Xinzhi Yixiangtu were originally published not as a series of loose prints but as a book. The sheets were folded in half so that, when assembled and bound, each engraved image was seen not as a whole but as two halves in different openings of the book. (If you look through Prints section you will see that all the sheets have a central fold.)
The sheet shown here reveals the construction of the book. The sheets were bound not with thread but using strips of paper ('paper screws') forced between the fibres of the sheet. There are therefore no punched holes and, since the paper closes up when the paper screws are removed, very little trace of the binding. But the evidence is there: near the edge of each side, two characteristic areas of distortion and tightness can be recognised.
This particular sheet showing a large astronomical sextant is also one of half a dozen in the set with a French translation of the Chinese inscription.