Bill,
Might I recommend the book "Modern Locomotive Construction, 1892" by J. G. A Meyer. This was reprinted by Lindsay Publications, Inc. Bradley, IL 60915, 1994, ISBN 1-55918-144-3. I found my copy at Caboose Hobbies in Denver.
This is an "What you have always wanted to know about Locomotives, but were afraid to ask".
Rick Steele