I guess I must have read this book in about 1987/88, as a fairly young Christian. It's a collection of essays, originally written for a competition, I believe, on the lives of significant pioneer missionaries and covers David Brainerd, William C Burns, John Eliot, Henry Martyn and John G Paton.
It made a real impact on me. Here were serious men, intent on serving Jesus irrespective of cost and their focus was on people who hadn't yet heard of Jesus.
I'm sure I read it with an unhealthy dose of romanticism and unrealism, which was my fault, not the book's. But its impact on me was significant.
You can still buy it.