This transformer converted 1,100 or 2,200 volt primary to about 110V for local electric customers. Such was commonplace practice in the earlier years of the electric utility industry (c.1890-1910s). In subsequent years higher primary voltages became the rule to keep up with increased demand, especially owing to the ever-increasing popularity of consumer appliances that operated electrically.

Note the "break-arm" on the pole on the right. It prpbably was routing for the two customer wires to the brick building on the right. In addition there is what looks like a telephone openwire subscriber lead along the left.