On a duck plant with a capacity of 50,000 ducks everything is on a big scale. Although ducks will stand more crowding than other kinds of poultry, it takes a large farm for so many. The buildings will cover many thousands of square feet of land and, though of the cheapest substantial structure, will represent an investment of fifteen or twenty thousand dollars. Incubators, appliances, breeding stock, and supplies on hand will amount to about as much. The incubator cellar will be several times as large as the cellar under the ordinary dwelling house. Before the so-called mammoth incubators were made, the largest-sized machines heated with lamps were used on all duck farms, and an incubator cellar would sometimes contain as many as seventy incubators having a capacity of from 200 to 300 eggs each. Now many of the large farms use the mammoth incubators, with a capacity of from 6000 to 18,000 eggs each. These mammoth incubators are really series of small egg chambers so arranged that the entire series is heated by pipes coming from a hot-water heater, instead of each chamber having an independent lamp heater as in the small, or individual, machines. [Illustration: Fig. 139. Feeding young ducks on farm of W. R. Curtiss & Co., Ransomville, New York] As nearly all kinds of supplies are bought by the carload, and as stocks must be kept up so that there will be no possibility of running short of foodstuffs, a great deal of space is required for storage. Large quantities of ice are needed to cool the dressed ducks before shipping them to market, so the farm must have its own ice houses and store its own supply of ice in the winter. For some years after duck farms grew to such large proportions, the mixing of mash was all done by hand, with shovels. Often one man was kept busy all day long mixing mash, and very hard work it was. Now the men on the large farms mix the food in big dough mixers, such as are used by bakers, and work that would take a man an hour is done in a few minutes.