[00:00.29]Lesson 17
[00:02.82]The longest suspension bridge in the world
[00:11.85]How is the bridge supported?
[00:16.64]Verrazano, an Italian about whom little is known, 
[00:20.79]sailed into New York Harbour in 1524 and named it Angouleme.
[00:28.39]He described it as 'a very agreeable situation located within two small hills in the midst of which flowed a great river.'
[00:38.48]Though Verrazano is by no means considered to be a great explorer, his name will probably remain immortal,
[00:47.53]for on November 21st, 1964, the longest suspension bridge in the world was named after him.
[00:59.30]The Verrazano Bridge, which was designed by Othmar Ammann, joins Brooklyn to Staten Island.
[01:07.76]It has a span of 4, 260 feet.
[01:12.55]The bridge is so long that the shape of the earth had to be taken into account by its designer.
[01:19.41]Two great towers support four huge cables.
[01:25.55]The towers are built on immense underwater platforms made of steel and concrete.
[01:32.33]The platforms extend to a depth of over 100 feet under the sea.
[01:37.64]These alone took sixteen months to build.
[01:41.46]Above the surface of the water, the towers rise to a height of nearly 700 feet.
[01:48.21]They support the cables from which the bridge has been suspended.
[01:52.63]Each of the four cables contains 26, 108 lengths of wire.
[01:59.09]It has been estimated that if the bridge were packed with cars,
[02:03.48] it would still only be carrying a third of its total capacity.
[02:09.74]However, size and strength are not the only important things about this bridge.
[02:15.89]Despite its immensity, it is both simple and elegant,
[02:21.44]fulfilling its designer's dream to creat 'an enormous object drawn as faintly as possible'.