"Think what a work this would be at the present day, and then remember that it was built two thousand years ago, when the science of engineering was in its infancy, and the various mechanical appliances for moving heavy bodies were unknown! "We spent a day at the Great Wall. We scrambled over the ruins and climbed to the top of one of the towers, and we had more than one tumble among the remains of the great enterprise of twenty centuries ago. Then we started back to Pekin, and returned with aching limbs and a general feeling that we had had a hard journey. But we were well satisfied that we had been there, and would not have missed seeing the Great Wall for twice the fatigue and trouble. They told us in Pekin that some travellers have been imposed on by seeing only a piece of a wall about thirty miles from the city, which the guides pretend is the real one. They didn't try the trick on us, and probably thought it would not be of any use to do so. "We did not stay long in Pekin after we got back from the Great Wall, as we had to catch the steamer at Tien-tsin. Here we are steaming down the coast, and having a jolly time. We are on the same ship that took us up from Shanghai, and so we feel almost as if we had got home again. But we are aware that home is yet a long way off, and we have many a mile between us and the friends of whom we think so often." CHAPTER XXIX. FROM SHANGHAI TO HONG-KONG.--A STORY OF THE COOLIE TRADE. The party reached Shanghai without accident, and on their arrival at that port the boys had a welcome surprise in the shape of letters from home. Their first letters from Japan had been received, and read and reread by family and friends. To judge by the words of praise that they elicited, the efforts of the youths at descriptive composition were eminently successful. Frank's mother said that if they did as well all through their journey as they had done in the beginning, they would be qualified to write a book about Japan and China; and a similar opinion of their powers was drawn from Fred's mother, who took great pride in her son. Mary and Effie composed a joint letter to Frank, to tell how much pleasure he had given them. They were somewhat anxious about the purchases, but were entirely sure everything would be correct in the end. Fred began to be a trifle jealous of Frank when he saw how much the latter enjoyed the communication from the girl who came to the railway station to see them off. He vowed to himself that before he started on another journey he would make the acquaintance of another Effie, so that he would have some one to exchange letters with.