Humayuns garden, apparently level, in reality slopes to the south, where the slight difference in the ground has been cunningly made use of to introduce tiny carved chutes down which the water ripples. At one or two places in the side walls there are longer water-chutes, where the water, which has been lifted up from great wells outside, rushes foaming down the carved stones into the garden. These marble or stone chutes were carved in various patterns, cut ingeniously at an angle so that the water running over them was thrown up and broken into ripples and splashes. Shell and wave designs were the favourites, and their name was as prettily fashioned as their carving-they were called chadars, meaning white 'shawls' of water. These water-chutes are a very characteristic feature of the Mughal gardens, and were used with much effect where the ground allowed of the garden being laid out in a series of high terraces. But in small gardens, or in the plains, even the slightest slope was made use of; only a foot or two of difference sufficed to create one of these charming little waterfalls, whose inspiration was directly drawn from memories of the dancing spray and white foam of mountain rivulets in the builders northern home.
A small pavilion stands on the terrace at the far side of the garden overlooking the plains and the river, which formerly ran much nearer to the walls. On the garden side it overlooks two large sunk plots, doubtless once laid out in parterres resembling those in the Anguri Bagh, so that on looking back, the mausoleum was seen across a blaze of flowers interspersed with cypress trees.
This enclosure, with its square plots and innumerable narrow watercourses, shows very clearly how all the details of the Mughal garden were evolved from the simple necessity of irrigation. In India the Hindus relied chiefly on their big rivers and the water collected in tanks during the heavy summer rainfall, but in Persia and Turkestan there are few rivers, so that numbers of artificial channels were made for irrigation and for the supply of water to the towns and villages. At first these Persian and Turki gardens, laid out after the old fourfold plan, were subdivided into numerous plots by the little water-runnels. In the richer gardens these tiny channels were edged with cut stone and further elaborated by the addition of small tanks and fountains. In Babars time the outline of the garden had not gone much beyond this.