Definition of "domeless"

For the most part they were small standard gauge 0-6-0 side tanks of the type illustrated, with long tapered chimneys and an unusual feature for the Continent in the shape of domeless boilers, the protuberance just behind the chimney being a sandbox.

1941 August, “Notes and News: The Swiss South Eastern Railway”, in Railway Magazine, page 376

The first 20 H1's delivered in 1929-1930 were of conventional, taut CPR stamp, (e.g., with Elesco heater, centered headlight, vestibule cab), but the next batch in 1937 introduced the railway's famous semi-streamlining pattern, keynoted by a smooth jacketing, recessed headlight, solid pilot, and domeless boiler.

1959, David P. Morgan, editor, Steam's Finest Hour, Kalmbach Publishing Co., page 113