Galvanic Cell (1 Viewer)

[hothand621]

Hey guys. For my chemistry practical we did a galvanic cell investigation, but in one electrolyte solution (NaCL). The electrodes were graphite and zinc. Can someone please explain how this even produces a reading on the voltmeter? There is a picture below?

 

[strawberrye]

The answer can be found in this thread http://community.boredofstudies.org/showthread.php?t=314846&highlight=graphite+electrode.... hoped this helps