In the early days baseball bats came in all shapes and sizes. In the 1850s baseball was an extremely young sport and batters made their own bats and experimented with bats of all varieties (long, short, flat, heavy). They quickly learned that bats with rounded barrels seemed to work the best. Some players would use a flat bat when called upon to bunt (baseball). By 1857, the sport's first governing body, the National Association of Base Ball Players, established a rule that "The bat must be round, and must not exceed 2 1/2 inches in diameter in the thickest part; it must be made of wood, and may be of any length, to suit the striker." (Section 2, Adopted at the Convention of Base Ball Clubs on 2/25/1857) In 1868, another rule was added that stated the bat could be no longer than 42 inches in length. In 1924 a patent was issued to William Shroyer for the first metal baseball bat. Despite this early patent, metal bats were not seen in the game of baseball until 1970, when Worth introduced the games first aluminum baseball bat. Easton arrived in the aluminum bat scene in the late 1970s with a stronger grade of aluminum that is credited with significantly increasing the popularity of aluminum baseball bats. Despite the popularity of the bats with the baseball players nationwide, Major League Baseball (for competitive and safety reasons) has never allowed anything other than wood bats to be used. In 1993 Worth and Easton both introduced Titanium bats, and in 1995 Easton and Louisville Slugger introduced the strongest, lightest grade of aluminum bats to date. Improvements to baseball bats continue today as developments such as double walled bats, scandium-aluminum bats, and now composite bats arrive in sporting goods stores.