Stenciled initials can be seen on the crossover arm facing you. They stood for the Edison Electric Illuminating Company (of Boston). This organization became Boston Edison in 1938. Lower voltage electric wires were strung to the older pole on the right. The top of a trolley service pole is seen in this image carrying four heavy direct current cables, possibly supported by CD 140 Jumbo insulators. Lowermost on the wooden pole (center) is a crossarm with smaller insulators (CD 104s) having twisted-pair telephone subscriber line pair tied to them.

That must be *one really cool* insulator...whatever it is! ...on the lower crossover arm on the left.....