The Old Farmer's Almanac is an almanac containing weather forecasts, planting charts, astronomical data, recipes, and articles. Topics include gardening, sports, astronomy, folklore, and predictions on trends in fashion, food, home, technology, and living for the coming year. Published every September, The Old Farmer's Almanac has been published continuously since 1792, making it the oldest continuously published periodical in North America. The publication was started by Robert B. Thomas and follows in the heritage of American almanacs such as Benjamin Franklin’s Poor Richard's Almanack. Early history (1792–1850) The first Old Farmer's Almanac (then known as The Farmer's Almanac) was edited by Robert Bailey Thomas, the publication's founder. There were many competing almanacs in the 18th century, but Thomas's upstart was a success. In its second year, distribution tripled to 9,000. The initial cost of the book was six pence (about four cents). To calculate the Almanacs weather predictions, Thomas studied solar activity, astronomy cycles and weather patterns and used his research to develop a secret forecasting formula, which is still in use today. Other than the Almanacs prognosticators, few people have seen the formula. It is kept in a black tin box at the Almanac offices in Dublin, New Hampshire. Thomas also started drilling a hole through the Almanac so that subscribers could hang it from a nail or a string. Thomas served as editor until his death on May 19, 1846. As its editor for more than 50 years, Thomas established The Old Farmer's Almanac as America's "most enduring" almanac by outlasting the competition. Becoming "Old" In 1832, with his almanac having survived longer than similarly named competitors, Thomas inserted the word "Old" in the title, later dropping it in the title of the 1836 edition. After Thomas's death, John Henry Jenks was appointed editor and, in 1848, the book's name was permanently and officially revised to The Old Farmer's Almanac. 19th and 20th centuries In 1851, Jenks made another change to the Almanac when he featured a "four seasons" drawing on the cover by Boston artist Hammatt Billings, engraved by Henry Nichols. Jenks dropped the new cover for three years and then reinstated it permanently in 1855. This trademarked design is still in use today. In 1858, Abraham Lincoln may have used a copy of The Old Farmer's Almanac to argue the innocence of his client, William "Duff" Armstrong, who was on trial for murder in Beardstown, Illinois.