HO Gauge turns 100 years old! Bing introduces it's new OO / HO line in 1922. Intially clockwork ..adding electrical trains in 1925..manufactured till 1932. Advertised as a table top railroad ..28" diameter ...which was basically the same size as current tin plate O gauge trains. The Bing line was moderately successive and planted the seeds for the gaint wave of miniaturization within the model train world that would emerge in the late 1930's.
Bing made export models for America with cowcatchers ( for miniature cows) and English Models with buffers. Ed Alexander lays claim for the first HO Gauge layout in America in 1925 ..he also carried the Bing line with his mail order business beginning in 1928.
Please see link for action packed video of "Clockwork HO"