Operum philosophicorum
Operum philosophicorum is a 1681 Latin collection of philosophical and astronomical works by Jean-Baptiste Du Hamel and Pierre Petit, printed at Nuremberg by Johann Ziegler's press for a scholarly readership of natural philosophers. The pictures are four woodcut decorated initials, a Q, O, C and H, with dense strapwork, scrolls and foliage set in plain square or round frames, offering designers a model for historical ornamental lettering.
