HEATING AND VENTILATING BROODERS. 315 



It is worth noticing that, owing to the fact that heat 

 rises to the top of the hover, the side heat plan is really 

 a combination plan as well as the other. One is a com- 

 bination of top and bottom heat and the other is a com- 

 bination of top and side heat. The writer unhesitatingly 

 prefers the Yon Culm plan to all others, provided that 

 the broods are small, never exceeding thirty chicks, and 

 twenty or less is better. This matter of size of the 

 brood is very important ; for when the source of comfort 

 is at the side, the chicks will, if lacking in warmth even 

 slightly, crowd towards it, and if numerous enough to 

 form ranks three or four deep, crush the inner rank 

 against the heat drum or tank and make it difficult for 

 them to get out into the fresh air. There is a similar 

 crowding closely to the body of the brooding hen, but 

 her brood of the normal number of twelve to fifteen can 

 all find room around her without a turbulent outer rank 

 of malcontents to make misery. The drum of the Yon 

 Culin brooder has an external surface considerably 

 greater than that of a hen, and a proportionate number 

 of birds can gather around it comfortably. We have 

 tried still larger drums to warm forty, fifty and sixty 

 chicks respectively, and they would all work as well as 

 the twenty-chick size if the chicks could be depended 

 upon to always range themselves evenly around it. In 

 fact, the drum might be as big as the Ferris wheel and 

 serve to warm an almost innumerable number if they 

 would all go to bed in single file with no crowding. 

 With only a score or so of birds and a drum of a size to 

 correspond, no large crowd in a riot is possible, while, 

 of course, the greater the whole number the greater the 

 throng that is liable to gather in one spot. A merit of 

 the side heat, hot-air drum is that, as the chicks increase 

 in size, bigger drums and covers can be substituted 

 without changing the lamp or dividing the broods. A 

 demerit is that since there is a difficulty in always gaug- 



