"Impromptu"; or, How to Think on Your Feet by Grenville Kleiser is a guide on the art of impromptu speaking, written in the early 20th century. The book serves as a manual for improving one's ability to think quickly and articulate thoughts clearly when speaking without prior preparation. It provides a structured approach to public speaking, emphasizing practice as a means to enhance mental agility and self-confidence. The content of the book explores various exercises and principles that can develop a speaker's talent for spontaneous oratory. Kleiser introduces a unique game wherein participants select topics at random and speak on them for one minute, thereby gaining invaluable experience in organizing thoughts quickly. The text includes example one-minute speeches on a variety of subjects, illustrating effective communication styles. Kleiser also stresses the importance of studying great orators, utilizing logic, deepening knowledge of various topics, and focusing on delivery to captivate and persuade an audience. The accompanying essay by Isaac Grant Thompson discusses the significance of eloquence in forensic speaking, further enriching the reader's understanding of public speaking's impact in both legal and public forums. (This is an automatically generated summary.)