{"value"=>"<p>This section contains correspondence, memoranda, notes, bids, agreements, photographs, patent papers, circulars, and scrapbooks regarding the invention and marketing of the Sprague-Pratt push button electric elevator, 1890-1898, and the Sprague dual elevator system, 1926-1932. Included are papers documenting installations in the Central London Railway and the Adams Express Building, New York City. Additional material on Sprague's elevator work can be found in the two previous sections, since much of this work was done under the auspices of the Sprague Electric Company.</p>"}