The quantity of grain to be given any flock of fowls must be determined by trial and observation. The grain should not be fed in troughs from which the birds can eat it very quickly, but scattered in the litter on the floor, so that the fowls will take exercise scratching it out, and eat slowly. There is an advantage in giving some soft and quickly digested food, but if too much of the food can be eaten quickly, the birds do not take exercise enough. When there is grass in the poultry yard, it is a good plan to scatter the grain in the grass sometimes in fine weather. The hens will find it all, and in scratching it out will bring up the dead grass, and a better sod will grow afterward. [Illustration: Fig. 78. Flock of Barred Plymouth Rocks] A dozen medium-sized fowls, if fed in the morning with the mash described above, would probably need a little over a pint of grain in the middle of the day and about a quart toward evening. An experienced feeder can usually tell by the eagerness of the fowls for their food whether to increase or diminish the quantity; but the most expert poultry keeper does not rely upon this kind of observation alone. Occasionally, before giving food, he looks in the litter to see if there is grain left there from previous feedings, and if he finds much, gives no more until the birds have eaten this all up clean. Water should be given as often as is necessary to keep the supply quite fresh. In cool (but not freezing) weather, once a day is usually sufficient. In hot weather the water should be fresh two or three times a day, in order that the birds may have cool drinks. In freezing weather many poultry keepers give the water warm, because then it does not freeze so quickly. The advantage of this is very slight, and wattles that are wet with warm water in extreme cold weather become especially susceptible to frost. It is not really necessary to give fowls water when they can get snow or ice in a form in which they can eat it. [Illustration: Fig. 79. Flock of Single-Comb White Leghorns] Hens that are laying must be well supplied with oyster shells or lime in some form for the shells of the eggs. They can get a part of the lime required for this purpose from the lime in foodstuffs, but not nearly enough to make good thick shells for all their eggs when they are laying well. Ground oyster shells are sold by all dealers in poultry supplies. [Illustration: Fig. 80. White Wyandotte hen and chicks]