Sometimes the wells of the kanaats are not more than twenty yards apart; sometimes as far off as fifty or even eighty. As each well is dug, the “mokennis,” or tunnellers, draw up from it all the earth, which they carefully place round it in a circle. As they come to water, the mud which is drawn up is poured on the earth, and as it hardens in the sun, a number of crater-like mounds are formed; these mark the lines of kanaats, which may be distinguished running across barren plains for many miles, or even farsakhs. They are often dry, and disused ones are rather dangerous. I once, when riding, went into an old one, horse and all, but managed to scramble out as my horse struggled; he plugged the well, and had to be, with some difficulty, dug and drawn out. A very curious accident happened to Mr. H⸺, of the Department, when coursing at Teheran. Fair coursing was obtained in the immediate vicinity of the capital, but the kanaat-holes rendered it somewhat dangerous. A run took place, and Mr. H⸺ was missed. His horse, riderless, joined the others, and the only conclusion was that he must have tumbled down a well-hole, which occur here in tens of thousands, and in every direction. After a long search his hat was discovered at the margin of one of the innumerable well-holes. That saved his life; for had his hat not been found, he would still be in the kanaat, as his voice would never have reached the surface. Stirrup-leathers were joined, and he was drawn out not much the worse, strange to say, though his face and hands were badly cut. To construct a kanaat is the highest benefit a rich man can confer upon a village; it at once becomes a flourishing place. Sometimes a long series of tunnels and wells are dug, and by some error in calculation there is no supply of water; but this is very rare. The great advantage of these subterranean channels is, that loss by evaporation is reduced to a minimum, and water cannot be stolen; of course the cost of making is very great; but if successful it is a very profitable transaction, for the ryots have to _buy_ the water, and at a high price.