Fifty-Seventh Street, New York, is a building of this type.

In this seeking for sunlight in our cities, we will come to live on
the roofs more and more--in summer in the free air, in winter under
variformed shelters of glass. This tendency is already manifesting
itself in those newest hotels whose roofs are gardens, convertible
into skating ponds, with glazed belvideres for eating in all weathers.
Nothing but ignorance and inanition stand in the way of utilization of
waste roof spaces. People have lived on the roofs in the past, often
enough, and will again.

[Illustration: PLATE X. RODIN STUDIOS, 200 WEST 57TH STREET, NEW YORK]

By shouldering ever upward for air and light, we have too often
made of the "downtown" districts cliff-bound canyons--"granite deeps
opening into granite deeps." This has been the result of no inherent
necessity, but of that competitive greed whose nemesis is ever to
miss the very thing it seeks. By intelligent co-operation, backed
by legislation, the roads and sidewalks might be made to share the
sunlight with the roofs.

This could be achieved in two ways: by stepping back the façades
in successive stages--giving top lighting, terraces, and wonderful
incidental effects of light and shade--or by adjusting the height of
the buildings to the width of their interspaces, making rows of tall
buildings alternate with rows of low ones, with occasional fully
isolated "skyscrapers" giving variety to the sky-line.

These and similar problems of city planning have been worked out
theoretically with much minuteness of detail, and are known to every