efficiency. There is an elevated road whose trains, like the surface
cars, are accommodated in the centre of the city by the subway. All the
various roads--surface, elevated (about 7 m., built 1896-1901), and
subway--are controlled, almost wholly, by one company. They all connect
and interchange passengers freely; so that the ordinary American
five-cent fare enables a passenger to travel between almost any two
points over an area of 100 sq. m. The two huge steam-railway stations of
the Boston & Maine and the Boston & Albany systems also deserve mention.
The former (the North, or Union station, 1893) covers 9 acres and has 23
tracks; the latter (the South Terminal, 1898), one of the largest
stations in the world, covers 13 acres and has 32 tracks, and is used by
the Boston & Albany and by the New York, New Haven & Hartford railways.

A noteworthy feature of the metropolitan public water service was begun
in 1896 in the Wachusett lake reservoir at Clinton, on the Nashua river.
The basin here excavated by ten years of labour, lying 385 ft. above
high-tide level of Boston harbour, has an area of 6.5 sq. m., an average
depth of 46 ft., and a capacity of 63,068,000,000 gallons of water. It
is the largest municipal reservoir in the world[3], yet it is only part
of a system planned for the service of the metropolitan area.

The park system is quite unique among American cities. The Common, a
park of 48 acres, in the centre of the city, has been a public
reservation since 1634, and no city park in the world is cherished more
affectionately for historical associations. Adjoining it is the Public
Garden of 24 acres (1859), part of the made area of the city.
Commonwealth Avenue, one of the Back Bay streets running from the foot
of the Public Garden, is one of the finest residence streets of the
country. It is 240 ft. wide, with four rows of trees shading the parking
of its central mall, and is a link through the Back Bay Fens with the
beautiful outer park system. The park system consists of two concentric
rings, the inner being the city system proper, the outer the
metropolitan system undertaken by the commonwealth in co-operation with
the city. The former has been laid out since 1875, and includes upwards
of 2300 acres, with more than 100 m. of walks, drives and rides. Its
central ornament is Franklin Park (527 acres). The metropolitan system,
which extends around the city on a radius of 10 to 12 m., was begun in
1893. It embraces