This was the post that I thought might help:
did you investigate the source of the number??
romeo and juliet should lead you to the babylonian door and after looking at the two bands, holmes will have some revelation so that when you go back to the library and go to one of the machines...
enter the number from the on-screen keypad and then pull the arm on the side...
the machine should direct you to a book on hindu enchantment...
you have the right number - but sometimes, in these games, having the right info doesn't mean anything if the character doesn't..
If none of this sounds familiar, then perhaps it would be a good idea to restore to a previous save (at a time when you were moving right along and not getting stuck), consult the walkthrough from that point, and follow each step carefully.
Alternatively, you could just revisit all of the areas available to you, click on whatever you can, and maybe that will trigger something and help you figure out what you might have missed.
Good luck.