"The Rover Boys at Big Horn Ranch; Or, The Cowboys' Double Round-Up" by Arthur M. Winfield is a novel written in the early 20th century. This book is part of a series following the adventures of the Rover boys, who are engaging, fun-loving cadets navigating through their school life and various escapades. The plot centers around Jack, Fred, and their cousins as they face challenges and embark on new adventures at the cowboy-themed Big Horn Ranch. The opening of the book presents the Rover boys enjoying a winter afternoon with a snowball throwing contest at their military school, Colby Hall. The boys enthusiastically join in on the fun, but their good-natured mischief leads to trouble when one of their snowballs accidentally strikes their strict teacher, Professor Duke. This incident escalates into a series of humorous yet precarious events, causing the boys to be locked up as a punishment. As tensions rise and they await their punishment, the stage is set for their adventure that will involve mystery and camaraderie as they navigate life in a military academy and the challenges that come with it. (This is an automatically generated summary.)