,000 more, of which it is the focus, so that the entire
city contains more than 14,500,000 souls. The several hundred square
miles of land and water forming greater New York are perfectly united
by numerous bridges, tunnels, and electric ferries, while the city's
great natural advantages have been enhanced and beautified by every
ingenious device. No main avenue in the newer sections is less than
two hundred feet wide, containing shade and fruit trees, a bridle-path,
broad sidewalks, and open spaces for carriages and bicycles. Several
fine diagonal streets and breathing-squares have also been provided in
the older sections, and the existing parks have been supplemented by
intermediate ones, all being connected by parkways to form continuous
chains.

"The hollow masts of our ships--to glance at another phase en
passant--carry windmills instead of sails, through which the wind
performs the work, of storing a great part of the energy required to
run them at sea, while they are discharging or loading cargo in port;
and it can, of course, work to better advantage while they are
stationary than when they are running before it. These turbines are
made entirely of light metal, and fold when not in use, so that only
the frames are visible. Sometimes these also fold and are housed, or
wholly disappear within the mast. Steam-boilers are also placed at the
foci of huge concave mirrors, often a hundred feet in diameter, the
required heat being supplied by the sun, without smoke, instead of by
bulky and dirty coal. This discovery gave commercial value to Sahara
and other tropical deserts, which are now desirable for mill-sites and
for generating power, on account of the directness with which they
receive the sun's rays and their freedom from clouds. Mile after mile
Africa has been won for the uses of civilization, till great stretches
that were considered impassible are as productive as gardens. Our
condensers, which compress, cool, and rarefy air, enabling travellers
to obtain water and even ice from the atmosphere, are great aids in
desert exploration, removing absolutely the principal distress of the
ancient caravan. The erstwhile 'Dark Continent' has a larger white
population now than North America had a hundred years ago, and has this
advantage for the future, that it contains 11,600,000 square miles,
while North America has less than 9,000,000. Every part of the globe
will soon sustain about as large and prosperous a