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The Harvard Bridge (also known locally as the MIT Bridge, the Massachusetts Avenue Bridge, and the "Mass. Ave." Bridge) is a steel haunched girder bridge between Back Bay, Boston and Cambridge, Massachusetts, US, carrying Massachusetts Avenue (Route 2A) over the Charles River. It is the longest bridge over the Charles River at .〔 It is locally known for being measured, inaccurately, in the idiosyncratic unit of length called the smoot.〔〔 After several legislative attempts fraught with antipathy on the part of Boston, it was built jointly by Boston and Cambridge, Massachusetts, between 1887 and 1891.〔 It originally included a swing span. The bridge was revised over the years until its superstructure was completely replaced in the late 1980s due to unacceptable vibration and the collapse of a similar bridge. The bridge was named for the Reverend John Harvard.〔 ==Conception== In the ''Acts of 1874'', the Massachusetts Legislature passed ''Chapters 175 and 314'' to authorize the construction of a bridge between Boston and Cambridge.〔Alger and Matthews, p. 5〕 Nothing further happened until 1882, when a follow-up law, ''Acts of 1882, Chapter 155'', with more specifics was enacted. The location was expressed as〔Alger and Matthews, pp. 5-6〕 The bridge was to have a draw with an opening of at least .〔 Boston did not like this Act, mainly because it did not provide for an overhead crossing of the Grand Junction Branch of the Boston and Albany Railroad. So nothing happened until the Act was amended by ''Acts of 1885, Chapter 129'', which changed the draw to a clear opening of at least and no more, until the other bridges below the proposed location were required to have a larger opening.〔Alger and Matthews, p. 9〕 Still nothing happened, until the City of Cambridge petitioned the Massachusetts Legislature in 1887 to compel Boston to proceed. This resulted in ''Acts of 1887, Chapter 282'', which was mandatory for both cities. It required that each city pay for half the bridge, and allowed Boston to raise up to US$250,000 (US$ with inflation) for this purpose, in excess of its debt limit. This implied an estimated cost of US$500,000 (US$ with inflation〔) for the bridge. The Act authorized a commission to build the bridge. The commission was to consist of the mayors of Boston and Cambridge plus one additional person to be appointed by the mayors. If the mayors failed to appoint a third commissioner, the governor was to do it for them.〔Alger and Matthews, pp. 10-12〕 The mayors of Boston and Cambridge, Hugh O'Brien and William E. Russell, appointed Leander Greeley of Cambridge as the third commissioner.〔Alger and Matthews, p. 13〕 This changed over time.〔Alger and Matthews, p. 31〕 The expectations of having built the bridge were clear.〔Alger and Matthews, p. 30〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Harvard Bridge」の詳細全文を読む スポンサード リンク
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