Great find "steamup". A reasonably complete explanation about the physics principles involved in the "Antratube". There must have been quite a number of experiments before the design parameters were established. Axeman-Anderson Associates, consulting engineers, is clearly identified as the designer.
[Edit] Looking closer at the report, Axeman-Anderson Associates did not design the boiler that A-A sells today. There were two different designs, #1 using a magazine to hold coal and #2 using an Archimedes screw to feed the coal. Axeman-Anderson designed #1. #2 the forerunner to today's A-A boiler was designed by the "Anthracite Industries Laboratory". Anthracite Industries Laboratory was located in Primos, Delaware County, PA. Google Maps now shows Primos as a housing development.
I'll digest the report and post a summary of the report.