The History behind the Fourth Day’s Code: Hobo Chalk Marks

Just how the hobo chalk marks system developed, nobody knows, but as a means of providing vital information (frequently as a matter of life or death – or prison) of often considerable complexity, it remains unparalleled. The marks were left on boxcars, signposts, town signs, mailboxes, and fence posts.— Excerpted from The Book of Codes, page 137.

Check out the fourth video.

Tips and Tricks for the Crack the Code Sweepstakes

While reviewing each day’s video, the pause/play button and forward/backward controls are your friends. Use them often and to great effect.

For those new to Twitter, here’s a great explanation of how to direct message.

If you miss your chance to send your solution to the day’s code, you’ll have more chances to win as the week progresses, with a big chance to win $100 in UC Press books at the end of the week in our Grand Prize Drawing. You can always find the rules for the Sweepstakes here.