Decoration
From 1700 onwards, there was a trend towards plainer watch cases that would slide smoothly in and out of the pocket. Until 1800, some cases were still being heavily decorated -- embossed with floral motifs or designs incorporating birds and animals. But by then, most of the finest watches bore extremely plain outer cases of high carat gold. Continuing through the 19th century, pocket watches continued to be unostentatious from the outside, their plainness sometimes relieved with a little engine-turned decoration.
Pair Cases
Introduced in 1675, the pair case saw the watch movement fastened with a hinge into a plain inner case of gold or silver, which was then kept inside an outer case. In early examples, this would be decorated with embossed work. There might also be a third case of dyed leather, shagreen -- shark or fish skin -- or tortoiseshell.
European Cases
From the 1750s onwards, European watch manufacturers developed a slimmer case with a hinged glass at the front and two hinged lids to the rear, the inner one with winding holes. Elsewhere, pair cases remained fashionable, except that the inner and outer cases were no longer separate but hinged together.
Hunter and Demi Hunter
By the late 18th century, the pair case had given rise to the so-called "hunter." This was a pair case watch, but with a mechanism that made the lid spring up whenever the owner wished to inspect the dial -- and in some cases, spring down again when he had finished, all at a touch of a button. It was called a "hunter" because a man on horseback could use it one-handed while still grasping his reins. In the 19th century, this in turn lead to the demi hunter -- or "half hunter." On these, the outer lid has an aperture for inspecting the dial. The design is attributed to Napoleon Bonaparte, who, it is said, sawed through the outer case of his own watch with a knife.