Re: Markers and class lights

Around the turn of the century (about 1890-1920 or so) the D&RG used Hanlan lamps with two round lenses on locomotives. Lamps had fixed brackets, and so were marked either Right or Left. Of course, where right & left were depended on whether the brackets were mounted on the side or front of smokebox, and on the side or rear of tender. They carried clear lenses, and had swinging filters inside, which were controled with a lever that stuck out under each lens.
The ones carried on the front would have clear lenses and green filters, to show classification. The ones on the tender would have clear lenses and red filters, for use as markers on an engine running light.
I'd attach photos, but can't seem to do it. And I don't have a URL to post them to.