Public folder not readable I want to exchange files between two users on the same mac.

To do so, user one copies the file into ~/Public folder. I double checked that the folder and all files are readable and writable by all users.

If I change to the second user, the folder is empty.

Any ideas what's missing?
BetaRide. There is a difference between shared and public folders. 

The Shared folder is located in the Users folder on your hard disk, with your home folder and the home folders of any other people who have accounts on your Mac. You can use the Shared folder to share files with other users on your Mac. The Shared folder is set up so that all users on your Mac can open files in the folder and copy files to it.

To view the Shared folder, click the desktop to make sure you’re in the Finder, choose Go > Computer, open the icon for your internal disk (usually named Macintosh HD), then open the Users folder.

The Public folder is located in your home folder. You can use the Public folder to share files with other people on your network. To share information in your Public folder, you must turn on file sharing in the Sharing pane of System Preferences. Your Public folder is set up so that others can see and copy its contents, but not make changes.

Your Public folder also contains a Drop Box folder. Other people can copy files to your Drop Box, but they can’t see its contents.

To view the Public folder, click the desktop to make sure you’re in the Finder, then choose Go > Home.