Two closeups of the venerable old castron bell luminaires,
with their cuplight-type diffuser bowls. They were the main fixture
on freestanding poles in the 40's. They were contemporaries of
the older gumballs.
The cuplights began to supplant them in the postwar years. I don't think bells ever appeared on utility pole masts. They were also rarely on major highways, although they didn't shy away from major secondary roads and did have a presense on the Belt Pkwy.
The Bells emerged from an older style fixture, shaped like an old fashioned telephone handset, with a big round globe-like diffuser. Their smaller diffuser, hidden from birdseye sky views, were probably designed with possible air-raid blackouts in mind.
There was actually a 2nd version of the old Bells, also known as "Mission Bells", A smaller, more cone-shaped Bell, known as Junior in an old Welsbach manual. The only surviving example we know of is in the northwest Bronx, on a disintigrating castiron longarm pole at Mosholu Ave and Post, a block west of Broadway.