In this game it has several places with safes. I assume you are by the one in the Professor's Office:
Zoom in on the wall safe and click on the dial. The code is in your journal, when you have clicked on the postcard; it reads: 832619. The symbols on the dial correspond to the following books on the list: Moby Dick-->Whale, The Origin of Species-->Monkey, the Bible-->Cross, The Iliad-->Trojan Horse, Alice in Wonderland-->Rabbit, and The Raven-->Raven. The symbols representing these books are: Whale=1, Monkey=2, Cross=3, Trojan Horse=4, Rabbit=5 and Raven=6. Click on the symbols in the order like above. Take all the items inside the safe and the three cylinders will go into your inventory.
Hope that helps, Let me know if you can continue, thanks!
GameHouse Evangelist
Posted on Sun May 29 10:58:41 PDT 2011