cars were hauled by horses to Central Square, then attached to electric cars from Allston for the remainder of the trip into Boston. On May 18, 1896, tracks opened from Union Square east along North Beacon Street and Commonwealth Avenue to Kenmore Square, merging with the existing tracks on Beacon Street. On June 13, the western terminal was also extended to just shy of Newton Corner (Nonantum Square). On November 8, 1897, Newton service via Commonwealth Avenue began running into the Tremont Street subway. A lengthy Nonantum Square– route via Allston, Coolidge Corner, and Park Square opened on August 4, 1900. On December 9, 1912, service was extended north to Watertown on the existing Galen Street tracks. During the early part of the 20th century, the line was also used for freight service. The Boylston Street subway was opened to an incline in Kenmore Square on October 3, 1914, with Watertown service via Brighton Center immediately routed into the new tunnel. The first use of high-capacity center-entrance streetcars on the BERy system was as trailers on the Watertown Line in mid-1915. On February 23, 1922, Oak Square short turns were extended to Watertown in the evening peak hour. The Blandford Street portal, on Commonwealth Avenue west of , opened October 23, 1932, marking the last change in the route of the service. In 1941, the line became the first line in Boston to have primary service with the new PCC streetcars, which replaced the Types 4 and 5 cars then in service. North Beacon Street line In June 1894, the West End applied for city permission to construct a line on North Beacon Street between Union Square and the Watertown border. The Newtonville and Watertown Street Railway soon secured position to build between and Union Square, with the intention to use the West End tracks to reach downtown Boston. After approval by the Watertown Arsenal (which owned a section of North Beacon Street) in 1896 – despite the objection of the West End – the company constructed the line in 1898. After further disagreements between its parent company Newton and Boston Street Railway and the BERy about operations, the line opened in 1900. Through service on the line between Watertown and the Tremont Street subway, acting as a branch of the Newton-Brighton line, began on November 18, 1900. The BERy took over the line from the Newton and Boston in