"Practical Talks by an Astronomer" by Harold Jacoby is a collection of engaging essays on astronomy written in the late 19th century. The work does not aim to serve as a comprehensive text on the subject; rather, it selectively explores intriguing topics within astronomy, using accessible language designed for a general audience. The book potentially appeals to readers who possess a casual interest in celestial phenomena without delving into overly technical detail. The opening of the work introduces the concept of using astronomy for navigation at sea, recounting historical methods and instruments used by maritime captains in times prior to modern navigation tools. Jacoby shares anecdotes from an old sea captain regarding how ships relied solely on a compass and observational techniques, like utilizing a sextant to measure the sun's position at noon, to determine their latitude, demonstrating the blend of history and science that characterizes the book. This approach highlights the practical significance of astronomical knowledge while piquing curiosity about the interconnections between science and navigation. (This is an automatically generated summary.)