"The dignity of the act is the deliberate, circumspect, open, and serene performance by these men in the clear light of day, and by a concurrent purpose, of a civic duty, which embraced the greatest hazards to themselves and to all the people from whom they held this deputed discretion, but which, to their sober judgments, promised benefits to that people and their posterity, from generation to generation, exceeding these hazards and commensurate with its own fitness."