It was soon seen that a safe covered passageway between the cars must be provided, particularly for limited express trains. Crude attempts had been made in this direction at different times. As early as the years 1852 and 1855 patents were taken out for devices which provided for diaphragms of canvas to connect adjoining cars and form a passageway between them. These were applied to cars on the Naugatuck Railroad, in Connecticut, in 1857, but they were used mainly for purposes of ventilation, to provide for taking in air at the head of the train, so as to permit the car windows to be kept shut, to avoid the dust that entered through them when they were open. These appliances were very imperfect, did not seem to be of any practical advantage, even for the limited uses for which they were intended, and they were abandoned after a trial of about four years. In the year 1886 Mr. Pullman went practically to work to devise a perfect system for constructing continuous trains, and at the same time to provide for sufficient flexibility in connecting the passageways to allow for the motion consequent upon the rounding of curves. His efforts resulted in what is now known as the "vestibuled" train. [Illustration: Pullman Vestibuled Cars.] [Illustration: End View of a Vestibuled Car.] This invention, which was patented in 1887, succeeded not only in supplying the means of constructing a perfectly enclosed vestibule of handsome architectural appearance between the cars, but it accomplished what is even still more important, the introduction of a safety appliance more valuable than any yet devised for the protection of human life in case of collisions. The elastic diaphragms which are attached to the ends of the cars have steel frames, the faces or bearing surfaces of which are pressed firmly against each other by powerful spiral springs, which create a friction upon the faces of the frames, hold them firmly in position, prevent the oscillation of the cars, and furnish a buffer extending from the platform to the roof which precludes the possibility of one platform "riding" the other and producing telescoping in case of collision. The first of the vestibuled trains went into service on the Pennsylvania Railroad in June, 1886, and they are rapidly being adopted by railway companies. The vestibuled limited trains contain several sleeping-cars, a dining-car, and a car fitted up with a smoking saloon, a library with books, desks, and writing materials, a bath-room, and a barber-shop. With a free circulation of air throughout the train, the cars opening into each other, the electric light, the many other increased comforts and conveniences introduced, the steam-heating apparatus avoiding the necessity of using fires, the great speed, and absence of stops at meal-stations, this train is the acme of safe and luxurious travel. An ordinary passenger travels in as princely a style in these cars as any crowned head in Europe in a royal special train.