The Solar headlights were very popular with teens Harley, Indian, Excelsior, etc. riders of the day and there were many variants.
The Hine – Watt Carbide cannisters were fare less common and are quite rare nowadays. This model B fits to the frame front down tube or sometimes even the left side rear fork tube. Most cannisters, like for example the Prestolites, are fitted horizontally across the handlebars but this H-W unit, at only 8″ high, will mount away from the bars giving a nice clean look with just the horn up top.