The manure is removed from stables where horses or dairy cows are kept and stacked in a heap, which should be covered and so protected from the rain whilst allowing a current of air to pass over it. The floor should be of good solid and smooth concrete, slightly sloped towards collecting grids, to which all the dark coloured manure liquid will find its way, and thence through pipes to a cistern to which is fixed a good-sized pump. Where cattle is kept for fattening purposes the manure is left to accumulate for several weeks before being removed; in this case a great deal of the liquid becomes lost, and provision need not be made for its collection. There should be separate heaps for horses and cattle.