The widespread interest which was being attracted throughout Europe to the subject of the care of the sick and wounded in war led to a series of experimental trials being carried out at the _Paris International Exhibition of 1867_, when, with the help of a short line of railway laid down in the exhibition grounds and of a goods wagon supplied by the Western of France Railway Company, a number of different systems were tested. On this occasion, also, a model of an American car fitted up with india-rubber rings for the handles of stretchers was shown. At this time, and for many years afterwards, the ideal arrangement was considered, on the Continent of Europe, to be one under which railway vehicles sent to the front with troops, supplies or munitions could be readily adapted for bringing back the sick and wounded on the return journey; and alike in Germany, Russia, France, Austria and Italy the respective merits of a great variety of internal fittings designed to adapt existing rolling stock, whether passenger coaches, luggage vans, Post Office vans or goods wagons, to the serving of these dual purposes formed the subject of much experiment and controversy. Rope cables across the roof of a goods wagon, with dependent loops of rope for the reception of the stretcher handles (as in the Zavodovski method); stretchers laid on springs on the floor, suspended from the roof either by strong springs or by rope, resting on brackets attached to the sides, or partly resting and partly suspended; and collapsible frames of various kinds, each had their respective advocates.[19] The use and equipment of ambulance or hospital trains constituted, also, a regular subject of discussion at all the international congresses of Red Cross Societies which have been held since 1869.