I saw and heard this instrument in a park near Issaquah, Washington, in August 1983.  Steam was generated by a propane-fired packaged steam boiler (for drycleaning applications) located in the back of the trailer. You can see the chimney if you look closely.  It was built by Arthur E. Davis, a computer programmer at the University of Washington in Seattle.  I believe that this was the first of three instruments he built; it's location today isn't known. (Click here to view the large image.)

Mr. Davis also built a new keyboard and console for the Delta Queen's calliope and later designed and built the world's largest and loudest steam calliope for the Mississippi Queen.  The MQ calliope was built in 1975 by Davis Calliope Works and went into service in 1976 aboard the steamboat Mississippi Queen, where it is still in use today.

Mr. Davis wrote to me in February, 2000 (reprinted in 000319 MMDigest):

Alas, the portable calliope shown on your web page was sold to a pizza company in Portland, Oregon, around 1984 or 1985 and I have lost track of it.  It was a prototype and my later whistle design and valves were much improved. We had a lot of fun with that one doing many parades, birthday parties, grand openings, fund raisers, etc.  Probably the best sounding and most refined calliope that I built was commissioned for the "General Jackson" steamboat, built and operated at that time by Opryland. -- Arthur E. Davis, Davis Calliope Works, Seattle, WA
 

Close up of valves and whistles.  This was the early valve design, in which the steam flows through a right-angle turn in the valve.  The diaphragm inside the valve is held in the closed position by compressed air.  To play the whistle the air pressure is vented to atmosphere, and then the steam on the other side of the diaphragm can pass to the whistle.  Electric valves (not shown) connect the diaphragm chamber either to atmosphere (note on) or to a compressed air supply (note off).  (Click here to view the large image.)

The later valve design permits the valve to be attached on the top of the steam manifold, instead of the side.  Both versions are shown below.

Please contact Jody Kravitz if you know where this instrument pictured above is today.

Travis Vasconcelos wrote in 981006 MMDigest about the Davis calliope aboard the  "General Jackson" at Opryland USA, Inc.:

...  it has been relegated to the visual status only, and does not play anymore.  The owners of the boat see no use in repairing it and removed the keyboard and player unit some years ago.  I think it only played for the first two seasons or so that the boat ran.  I have made many attempts to get them to repair the calliope.  But, to this date all letters have gone unanswered. ... That Mississippi Queen Calliope is Arthur Davis' finest calliope ever. ...

Don Elbers maintains the calliopes aboard the steamboats operated by Delta Queen Steamboat Company.  He writes:

None of the original whistles on the Mississippi Queen calliope have been replaced -- they  are all original Arthur Davis whistles.  They have been repaired (like the one smashed in the wreck) and machined for voicing.  The Davis whistles are beautifully machined.  The stems have lathe cut threads.  Every single component is stamped with a matching number.  The skirts of the bells are rolled to perfection.  Even the smallest whistles have spokes (as do the original Thomas J. Nichol whistles), so that when the bells are rotated the bottom of the bell stays concentric with the annular ring through which the steam passes.