The Circus in Miniature: the Howard Bros. Circus Model (Book).
Copyright 2008 The John and Mable Ringling Museum of Art
Author Deborah W. Walk
ISBN 9780916758608

From the back cover:
"The Howard Bros. Circus Model, built by Howard Tibbals, is the world's largest miniature circus. Covering over 3,800 square feet, it is a replica of the Ringling Bros. & Barnum & Baily circus under tent. With over 42,000 objects in all, it includes not only the big top, menagerie, and sideshow tents, but also 55 railroad cars, 152 wagons, and 900 animals. Each tent and wagon is equipped exactly like the real circus from the steam kettles in the cookhouse tent to the 7,000 folding chairs in the big top. So step right up and tour the incredible Howard Bros. Circus Model."