Photograph of a 100-egg hot-water incubator by Spratt's Patent Ltd from the early/mid 20th century.

Illustration of a "Gloucester" mammoth incubator that had a capacity for 6000 eggs which was installed at Jack Wrenmall's Poultry Farm, Barton, Preston, Lancashire in 1927. According to the text beneath the image, it did so well that the farmer added a top tier increasing the capacity to 12000 eggs.

Illustration of an Anthracite brooder stove in an incubator with numerous chicks standing around its base in the early/mid 20th century.

Photograph of a baby mammoth 900-egg incubator in a barn in the early/mid 20th century.

Photograph of a poultry battery brooder - electric multiple brooder housing chicks in a shed in the early/mid 20th century.

Photograph of a poultry brooder in a field in Boghall, [Scotland] in the early/mid 20th century.

Photograph of turkeys being reared on wire in a brooder at Midland College in 1937.

Photograph of a man and woman looking at eggs in the "Buckeye" Mammoth incubator in the early/mid 20th century.

Photograph of a hen house with a sun porch for intensive rearing in a field on a farm in the early/mid 20th century.

Illustration of an outdoor hot-air brooder by Harry Hebditch, Ltd from the early/mid 20th century.