At the time this photo was taken, Bluffton, Indiana was still using the old 6.6A series street lighting loop, which only a few cities and towns were using at the time. The street lighting circuits were changed over to modern parallel circuit system a few years after the photo was taken.

In this shot is a series lighting circuit regulator pole with the constant current regulator and other gadgets. The light green device right below the distribution transformer (that's on top) is a photoelectric lighting control that activates an oil switch that turns on the constant current 6.6A regulator for the series lighting loop. Thanks to Joe Maurath for that added info.

The gear on the left (middle crossarm, the two units side-by-side) are instrument transformers. These are connected to the overhead primaries that operate the series lighting system, electrically before all of the street lighting gear on the pole. The secondary side of the instrument transformers proportionately reduce the voltage and amperage of the high voltage side (the primaries that run this system) for recording kilowatt hour usage; there was a kilowatt hour meter lower on the pole. Thanks more to Joe Maurath for that added info.

Note on the next pole back a U-399B loop insulator on the top right.

September 24, 2013