Today is Friday the 13th. For those who are superstitious it is a day to particularly avoid black cats and ladders. Historically Friday was considered unlucky, as well as the number 13; combine the two and you are asking for trouble. We have three this year. Today is our second Friday the 13, the last falling in June. It has been suggested that the popular novel published in 1907 titled Friday, the Thirteenth, was responsible for making the day popular. In the book, an unscrupulous broker takes advantage of the superstition to create a Wall Street panic on a Friday the 13th.