152 OUR DOMESTIC BIRDS 



shrink a great deal in weight. Visitors who come merely out 

 of curiosity are not desired on duck farms at any time, and 

 none but those familiar with the handling of ducks are ever 

 allowed to go about the farm without a guide who will see that 

 the ducks are not disturbed. Many visitors think that this is 

 unreasonable, but the duck grower knows that the mere pres- 

 ence of a stranger excites the ducks, and that a person walking 

 about might put a flock in a panic which would at once extend 

 to other flocks, simply because he was not familiar enough with 

 the ways of ducks to detect the signs of panic in a flock which 

 he was approaching, and to stand still until they were quiet, 

 or move very slowly until he had passed them. If a stranger, 

 walking between yards where there were five thousand ducks 

 fattening, made an unconscious movement that set the ducks in 

 motion, the loss to the grower could hardly be less than from 

 five to ten dollars, and might be very much more. Where such 

 little things can cause so much trouble and loss, the difference 

 between success and failure may lie in preventing them. 



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 incuba- 

 tors, with a capacity of from 6000 to 18,000 eggs each. These 

 mammoth incubators are really series of small egg chambers so 



