_Housing Required for Breeders._ In figuring on the amount of housing required for this number of breeding ducks, it is necessary to figure on 2-1/2 to 3 square feet of floor space per bird, 3 square feet being better than 2-1/2. This would require a housing space 20 feet deep by 120 feet long. However ducks are not usually housed in one building of this size, and in fact it is better not to do so since the smaller the flock of breeders kept together the better they will do. In no case should a duck raiser run more than 400 ducks in a flock and it is very much better to run them in pens of 100 each. In fact, some breeders do not place more than 25 to 50 breeding ducks in a pen. _Incubator Capacity._ Incubators are used exclusively for hatching the eggs. At the present time in practically all cases some form of hot water mammoth incubator is utilized for this purpose. An investment is required both in incubators and in a cellar in which to operate them. In figuring on the incubator capacity necessary to take care of a proposition of this size, it is necessary to base the estimate on the number of eggs produced during the season of flush production. The duck raiser figures on incubating all eggs suitable for the purpose rather than to sell any of them for other purposes as there is a greater profit in rearing and marketing the ducklings. For that reason he must have incubator capacity enough to take care of all the eggs laid at any time of the year. During the season of flush production the yield will ordinarily run in the neighborhood of 80%. The period of incubation is 28 days but 2 days more should be added to this to allow for cleaning out the machines, etc., before starting another hatch. This means that there would be 30 days between hatches. Figuring on 800 ducks with an 80% production for 30 days an incubator capacity of around 19,200 eggs would be required.