Childcraft – The How and Why Library

Multi-volume illustrated anthology for children, originally created in the 1930s by W. F. Quarrie & Company. Nowadays it's published by World Book, Inc. Originally the library consisted of seven volumes, and grew to 15 volumes in the 1950s. Currently the set consists of 12 volumes. Beginning 1965, they also have published a special, separate annual every year. https://store.worldbook.com/products/childcraft-how-and-why-library