After the invention of the magnetic compass and its first use in Italy for travel in the 16th century, a ship's course could be constantly monitored, leading to exploration and world trade. This intriguing guide explores a wide range of fascinating pocket compass types. Examples shown date from the late 1700s to the 1940s, with a focus on the mid-1800s and early 1900s. Hundreds of compasses are discussed with 507 colorful illustrations and detailed descriptions. The history of their development is explored, special uses for signal corps and civilian groups are presented, and patented improvements are featured. Cases for compasses include wood, leather, and brass in distinct styles around the world. The variety of craftsmanship quality, style, and value can help to identify origin and make collecting enjoyable and rewarding.