Percy F. Westerman 
Wilmshurst of the Frontier Force [PDF ebook] 

In the early decades of the twentieth century, member of the Royal Navy and lifelong seaman Percy F. Westerman began writing juvenile action-adventure novels, drawing on his own experiences during World War I and in other theaters of war. He achieved widespread acclaim and the undying devotion of millions of young readers. In this installment of the series, an intrepid crew of men plays a critical part in a campaign in Africa.