The key equipment used in baseball are the bat, gloves, mask, and the ball itself. The evolution of this equipment can be traced from the 19th century itself, right from the conception of the game. However, in those times no helmets were used.
The bat dimensions were finally agreed during the first baseball convention in 1857. The dimensions were described as round, not to be more than 2.5 inches around in its thickest part, and the length could be decided according to the suitability of the striker. However, during the 1868 season, it was decided that the bat could not be longer than 42 inches.
Though it is not possible to pinpoint the first player to wear a glove, but reports indicate that it was as early as 1860 when catchers wore them. In 1885, Arthur Irwin, in order to protect his two broken fingers, added 'padding' to his buckskin glove. This is probably the first instance of a player introducing noticeable padding to a glove.
As the evolution of the glove progressed, the National League and American Association of Baseball Clubs instituted a rule in 1895, which stated, "The catcher and the first baseman are permitted to wear a glove or mitt of any size, shape or weight.
All other players are restricted to the use of a glove or mitt weighing not over ten ounces, and measuring in circumference around the palm of the hand not over fourteen inches." This would be the rule for the rest of the 19th century.
The catcher's mask was first worn by Jim Tyng of the Harvard University Baseball Club in a 7-6 exhibition game loss against the Boston Red Stockings in May 1876. It is said that Tyng's roommate and team captain Fred Thayer invented the mask in 1875.
Thayer modified a fencing mask, which enabled Tyng to move closer to home base and receive the ball without fear of being struck in the face. Tyng also wore a small padded glove in the game.
The Knickerbocker Baseball Club introduced the uniform on April 24, 1849. It consisted of long blue woolen pants, leather belts, white flannel shirts with a full collar, and straw hats. At the end of the 1850s, many teams adopted the flannel shirt with the button on shield style, which contained the team's emblem, name, or both.
The full-length pantaloon pants were in fashion throughout the 1860s, but presented a problem, as the players would get their feet caught on the legs of the pants when running. Hence, players were forced to wrap them tight to their shins and use tape or a small belt to hold them.
In 1868, Cincinnati Red Stockings became the first team to wear knickers. These pants were less restrictive, and as a result their stockings or socks, were now visible. The uniforms are probably the only aspect of the game that has evolved so drastically from the game's conception to the present era.
During the first baseball convention in 1857, the diameter of the ball was voted on to be between ten and ten and one-quarter inches in circumference, and weigh between six and six and one-quarter ounces.