Value of 1947 Compton's Pictured Encyclopedia?

I have a full set of Compton's Pictured Encyclopedias and Fact Index, the 1947 edition. They are in great condition and I have volumes 1 through 15, the full set. I would love to hear some input about these books. If someone knows the value or if I should at least check on the value of them. Thank you so much.

By Christina J