It is well that these and other proposals for improvement, which are constantly invented or advocated, such as combining sight with sound at the signals, and the use of detonators, mechanically applied, to supersede the use of fogmen, should receive full consideration and discussion, after the experience of so terrible an accident, caused mainly by the failure of existing signal-arrangements. But, in the course of such deliberations, the facts must not be lost sight of, that men are still liable to make mistakes, machinery is still liable to fail, and further complication is by no means certain in all cases to produce greater safety.