Babe Ruth and Popular Science Magazine

One of my eBay students is trying to find the value of something he owns but hasn’t had much luck. I’m wondering if you can help.

This student has a Popular Science magazine from 1921 with Babe Ruth on the cover. Here is the info he provided:

Title: Popular Science Monthly

Date: Oct.21,1921

Vol 99 No. 4

Cover: Picture of Babe Ruth with bat in hand taking nerve & muscle tests at Columbia University

Feature Story: Babe Ruth’s Home Run Secrets Solved by Science. Article by Hugh S. Fullerton

Please let me know if you have any ideas on its value …. Thanks so much!