The style of harnessing is the most curious of all. A loop of rope is fastened to the extreme end of each shaft, and a long, rounded cross-bar is passed through the two loops. Two mounted Mongols lay the bar across their knees in the saddle, but no draught animal is put between the shafts. A rope is fastened to each end of the cross-bar and two other riders wind these ropes twice round their bodies. They have all riding whips, and when all is ready the four riders dash at full speed over the steppe, dragging the cart after them. Twenty other Mongols ride on each side, half hidden in clouds of dust. Suddenly two of them ride up beside the men who hold the cross-bar on their knees. Of their own accord the two fresh horses slip their heads under the bar, letting it fall on to the riders' knees, while the men who are relieved hold in their horses and let the cart roll on. These then join the rest of the troop. The cart does not stop during this change of horses, which is accomplished in a couple of seconds, and a furious pace is always kept up. In the same way the two front riders and their horses are relieved without stopping. When one of them is tired, a fresh rider comes forward and winds the rope round his waist. After two or three hours a village of several tents is seen on the steppe ahead of us. About thirty horses are held in readiness by the headman of the village, who has been warned the day before by the messenger. At every stage a few roubles[16] are paid to the Mongol attendants. This payment has always to be made in silver roubles, for the Mongols will not take paper money or small coins. Thus we go on and on, it would seem interminably, over the boundless steppe--each day the same bumping and jolting, each day the same monotonous landscape. In northern Mongolia, however, snow lay deep on the ground, and here the cart was drawn by men on camels. By this time I was so bruised and worn out with the continual jolting that it was a pleasure to drive on the soft snow. MARCO POLO