The experimental trials at the Paris Exhibition of 1867 were followed by the appointment in _Prussia_ of still another Commission of inquiry, and, acting on the recommendations of this body, the Prussian Government adopted the "Grund" system, under which the stretchers whereon the recumbent sufferers lay in the goods wagons or fourth-class carriages were placed on poles resting in slots over the convexity of laminated springs having one end screwed into the floor while the other, and free, end was provided with a roller designed to respond to the varying conditions of weight by sliding to and fro. This was the system mainly used in the "sanitary trains" of the Germans in the _Franco-Prussian War of 1870-71_. It was criticised on the ground (1) that the sick and wounded were still subject to the same jolts and concussions as ordinary seated passengers; (2) that the number who could be carried per carriage or wagon was very small, since it was still the case that only the floor space was utilised; and (3) that it was inconvenient for the doctor and the attendants to have to kneel down in order to attend to the patients.[20] Apart from these disadvantages, the ambulance service of the Germans was well organised during the war. Of ambulance trains, fitted up more or less as complete travelling hospitals, twenty-one were run, and the total number of sufferers removed by rail is said to have been over 89,000. Owing to traffic congestions, the transport to Berlin of wounded from the army engaged in the investment of Paris occupied no less a period than six days; but these journeys were made in the special ambulance trains which, provided in the later stages of the war, ensured full provision for the feeding, nursing and general comfort of the sufferers. The fact that such journeys could be undertaken at all showed the great advance which had been made since the battle of Sadowa, when most of the wounded could be conveyed no further than to cottages and farm-houses in neighbouring villages.