All of the street series fixtures in our area were mounted at what I call "series height" which was usually only 14 to 18 feet from the ground. When a lamp needed replacement the troubleman would extend a long wooden stick with a special clamp at its end so it could grasp the lamp's socket. This clamp had a wire cage-like assembly with a rope attached to it - pulling on the rope held the cage assembly closed to grasp the socket while pulling out or reinstalling the socket. I was always highly entertained by watching this maneuver, especially when the socket was reinserted and made contact, brilliantly lighting up the surrounding area. The nice thing about series incandescent lamps is their small, concise filaments which threw neat shadows at night, especially when surrounded by maple trees, which were so common in the area. Even though the 1000 lumen series lamps and their 120-volt multiple counterparts (92 watts) had manufacturers' light output published as equivalent, the series lamps always seemed to throw much more light.
The multiple incandescent luminaries used the same 4-foot, 3/4" galvanized steel arms the series ones used, right down to the 90-degree bend at the end. These were operated in groups from pole-mounted Fisher Pierce 30-ampere capacity meter socket-type photocontrols. These installations dated from the late 1940s and 1950s. These fixtures were simple, can-shaped cast aluminum heads and came in 2 versions - a short one and a taller one. Like other Wheeler components, they were prominently embossed WHEELER BOSTON. These multiples were internally wired and accommodated a porcelain socket that plugged into the fixture like the series ones. The multiple sockets sometimes were made of Bakelite also; and all had two separate brass prongs that fit into the fixture's porcelain receptacle. All these fixtures either had radial wave or porcelain enameled "half-moon" reflectors. The latter were used with the higher output 2500 lumen lamps, which were 189 watts and had slightly larger outside bulbs than their 92 watt, 1000 lumen counterparts. In the early 1960's, 1-1/4 inch diameter six-foot aluminum style arms were becoming the standard in our city, with a side-mounted aluminum Wheeler fixture having its own photocontrol integral with the head. Many of these circa 1962-1965 photocontrols were 500-watt Fisher Pierce models; internally painted red. These photocontrols really stood out when they were new and very much captured my attention! They were a bit taller than the photocontrols we know of today; except for the Fisher Pierce "Photofeedback" style, also introduced about 1962, which were about today's size. The red ones were also used on the new, shiny aluminum General Electric "cobra" style fixtures our utility was installing and some still remained in service here and there until they converted their remaining mercs to HPS during the mid- to late 1980s.
Also used were aluminum head fixtures with differing glass refractor designs that housed higher light output multiple operation incandescents. Most interesting were the General Electric Form 109 incandescents. These were outfitted with 6000 or 10,000-lumen lamps mounted vertically inside their fixtures. All these were operated in groups from a high-ampere output photocontrol. There were other larger fixtures made from the late 1940s into the 1960s by both Westinghouse and Wheeler. These fixtures replaced similar series fixtures, some of which were quite ornate and otherwise had similar light output. When mercury street lighting became more common after World War II, mercury lamp and fixture design technology were constantly and rapidly evolving, providing a lot of different mercury vapor streetlights to look at in the 1960s. Among my favorites were the 400-watt mercury General Electric Form 109, which had a separate ballast and photocontrol. These were introduced around 1948 and the lamp socket in these was mounted horizontally right inside the reflector/refractor canopy, so one would have to first unlatch the reflector and then reach into it to re-lamp. General Electric made these until around 1955 when the Form 400 came out, although these also required a separate ballast and photoelectric lighting control.
My fascination with mercury lamps
Another common luminarie in the area were Wheeler self-contained units with a photocontrol receptacle on top, integral 100 or 175-watt ballast, a smooth faced aluminum reflector (which snapped onto the head), in turn supporting a thick glass Holophane (supplied by Line Materials Company, with their logo on the glass) open-bottom refractor. These fixtures ran along a few of the main roads in the city and looked similar to later "yard lights". The major exception was that these utilized Wheeler cast aluminum round-sided fixtures. A few were of slightly later vintage (early 1960s) that were straight sided with a six-sided molding beneath the photocontrol receptacle. I derived a lot of pleasure standing beneath one of these fixtures at dusk watching the mercury lamps in these, in plain view, come up to full brilliance. Our utility used phosphor-coated lamps and the outer bulbs were of the bulged-tubular (BT) design with the end portion of the bulb clear. When the lamp first came on, the blue arc tube inside radiated a rich pinkish hue to the surrounding lamp phosphor. As the lamp warmed up to full brightness during the following few minutes the adjacent phosphor started to glow to more of a bright bluish color, harmonizing with that of the arc tube. This phenomenon always was and still is a thrill to this day to observe. Some of the older open bottomed fixtures in our city had the original mercury lamps in them that refused to burn out. You could look right up into the fixture and see the semi-bright blue arc tube and light greenish surrounding lamp phosphor. These "dim-outs" usually were earlier color improved phosphor lamps which produced sort of a limey-green colored light when they had an excessive number of hours accumulated upon them. I favored these because they made for easy, glare-free night observation.