operated, to read that in this case the fog was "so thick that the tail-lamp was not visible from an approaching train for more than a few yards." [24] Speaking of the modifications introduced into his brake by Westinghouse since 1874, Mr. Thomas E. Harrison, civil engineer of the North Eastern Railway Company in a communication to the directors of that company of April 24, 1879, recommending the adoption by it of the Westinghouse, and subsequently ordered to be printed for the use of Parliament, thus referred to the triple valve: "As the most important [of these modifications] I will particularly draw your attention to the "triple-valve" which has been made a regular bugbear by the opponents of the system, and has been called complicated, delicate, and liable to get out of order, etc. * * * It is, in fact, as simple a piece of mechanism as well can be imagined, certain in its action, of durable materials, easily accessible to an ordinary workman for examination or cleaning, and there is nothing about it that can justify the term complication; on the contrary, it is a model of ingenuity and simplicity." [25] During the six months ending June 30, 1879, some 300 stops due to some derangement of the apparatus of the Westinghouse brake were reported by ten companies in runs aggregating about two million miles. Being one stop to 6,600 miles run. Very many of these stops were obviously due to the want of familiarity of the employés with an apparatus new to them, but as a rule the delays occasioned did not exceed a very few minutes; of 82 stoppages, for instance, reported on the London, Brighton & South Coast road, the two longest were ten minutes each and the remainder averaged some three or four minutes.