View West toward Bay Bridge and City from Yerba Buena Island [Each individual tower of the bridge, standing more than 700 feet high from the base of its pier on the floor of the bay to its tip, represents a construction job comparable to that of a great skyscraper 60 stories high. The two suspension bridges have 2310 foot main spans. The lower deck carries two tracks for interurban electric cars and three lanes for heavy trucks, and the upper deck carries a 53-foot highway for six lanes of automobiles No. 25]