"Now, as soon as the mills are built, perhaps a blacksmith sets up a shop near them. If a blacksmith is going to open a shop anywhere in that town, it will be better for him to have it near the mills, because, as the farmers all have to come to the mills at any rate, they can avail themselves of the opportunity, to get their horses shod, or to get new tires to their wheels, when they are broken." "Tires?" repeated Marco. "What are tires?" "They are the iron rims around wheels. Every wheel must have an iron band about it, very tight, to strengthen it and to hold it firmly together. Without a tire, a wheel would very soon come to pieces, in rattling over a stony road. "Besides," continued Forester, "there is a great deal of other iron work, which the farmers must have done. Farmers can, generally, do most of the wood work which they want themselves. They can make their rakes, and drags, and cart-bodies, and sleds, and tool handles; but when they want iron work, they must go to the blacksmith's. They can make a harrow-frame, but the blacksmith must make the teeth." "Now I should think," said Marco, "that it would be easier to make the teeth than the frame." "Perhaps it is as easy, if one has the forge and tools," replied Forester; "but the tools and fixtures, necessary for blacksmith's work, are much more expensive than those required for ordinary wood work. There must be a forge built on purpose, and an anvil, supported on a solid foundation, and various tools. All these are necessary for shoeing a single horse, and when they are all procured, they will answer for all the horses of the neighborhood. Thus it happens, that though farmers do a great deal of their wood work themselves, at their own farms, in cold and stormy weather, they generally have their iron work done at a blacksmith's at some central place, where it is easy and convenient for all of them to go." The above conversation took place between Marco and Forester, as they were walking along together through the village, toward the part of the town where the mills were situated. Just at this moment, Marco happened to cast his eyes across the street a short distance before them, and he saw a fire on the ground in a little yard. He asked Forester what that fire could be. As soon as Forester saw the fire, he exclaimed, "Ah! they are putting a tire upon a wheel; that's quite fortunate; we'll go across and see them."