What's the earth made of? 

 - Washington, DC:  National Geographic Society,  1995. 
 - 1 VHS-28 min.:  sd., col. 
<br/><br/> Joins young explorer as he visits an active volcano, learns about the mid-ocean ridge, and talks with experts-all in an effort to find out about our planet's inner workings. 
<br/><br/><label>ISBN: </label>0792229274 
<br/><br/><label>Dewey Class. No.: </label>551.2