Boston Edison almost exclusively used glass insulators for their primary and secondary lines. More specifically these were double petticoat, deep groove styles (typically CD 164, 165.1 and 167) for their lower voltage routes and a number of Kimbles were bought by them through the 50s-early 60s for higher voltage primaries. A great many CD 164 Brookfields, Gayner-38-40s, No Name 38-40s, Lynchburg-38s (the latter all were SB), etc, were reused and carried over well before the company purchased the Edison Electric Illuminating Company of Boston in 1938. Thousands of these glass insulators remain in service on their pole lines (Eversource is the utility now). Glass insulators have been transferred to new poles and this practice is still in place to this day :-)
At some point during the teens the former company began to standardize their distribution insulators and ditch anything that was not of the "double-petticoat, deep groove" style whenever they were doing pole changeovers, upgrades and otherwise whenever encountered. This included CD 134s, 162s, etc., from earlier construction.
Newton is a Boston suburb, about 20 miles west of the city.