Typewriter the first major typewriter with these features. However, older "nonvisible" models continued in production to as late as 1915. A significant innovation was the shift key, introduced with the Remington No. 2 in 1878. This key physically "shifted" either the basket of typebars, in which case the typewriter is described as "basket shift", or the paper-holding carriage, in which case the typewriter is described as "carriage shift". Either mechanism caused a different portion of the typebar to come in contact with the ribbon/platen. The result is that each typebar could type two different characters, cutting the number of keys and
Cylindrical harmonics Cylindrical harmonics In mathematics, the cylindrical harmonics are a set of linearly independent solutions to Laplace's differential equation, formula_1, expressed in cylindrical coordinates, "ρ" (radial coordinate), "φ" (polar angle), and "z" (height). Each function "V"("k") is the product of three terms, each depending on one coordinate alone. The "ρ"-dependent term is given by Bessel functions (which occasionally are also called cylindrical harmonics). Each function formula_2 of this basis consists of the product of three functions: where formula_4 are the cylindrical coordinates, and "n" and "k" are constants which distinguish the members of the set from each other. As a result