Mark Twain, the highest-paid writer in America in 1894, was also one of the nation’s worst investors. “There are two times in a man’s life when he should not speculate,” he wrote. “When he can’t afford it and when he can.” After losing hundreds of thousands of dollars back when a beer cost a nickel, he found himself neck-deep in debt. His heiress wife, Livy, took the setback hard. She wrote, “I cannot get away from the feeling that business failure means disgrace.” Twain vowed to Livy he would pay back every penny. So, just when he imagined he would be settling into literary lionhood, he forced himself to mount the “platform” again. He did what no author had ever done, he embarked on a round-the-world stand-up comedy tour. Richard Zacks’ book “Chasing the Last Laugh,” chronicles this poignant chapter in Mark Twain’s life.