I discovered the following information while perusing my personal
library.  There were at least two steam calliopes at the 1876
Centennial Exhibition held in Philadelphia:

  "Children dragged their parents to the nearest sugar popcorn stand,
where they could buy red, white, and blue popcorn balls.  Hudnut's soda
fountain was the largest in the world and certainly the noisiest, since
it had a huge steam calliope.  Unfortunately, the calliope player knew
only three songs: 'Hold the Fort,' 'In the Sweet Bye and Bye,' and
'Listen to the Mocking Bird.' "

  "At 10 p.m. a cannon was fired to announce the Mardi-Gras Pageant
through the streets.  Three bands, including a mechanical steam
calliope that could be heard ten miles away, guaranteed that no one
would sleep through the big event."

(From: "The Way It Was -- 1876" by Suzanne Hilton.  Philadelphia:
The Westminster Press, 1975.  Pages 193 and 197)

Joyce Brite
Player Piano and Mechanical Music Exchange
http://mmd.foxtail.com/Exchange/

 [ Read "Harmony in Steam", an early account of Joshua Stoddard's
 [ steam calliope at  http://mmd.foxtail.com/Calliope/  -- Robbie