Sholes and Glidden typewriter length. The redesigned platen also introduced the modern spacing functionality (horizontal and axial movement providing letter and line spacing, respectively). The cylindrical platen became "an indispensable part of every standard [typewriter]". By the end of 1872, the appearance and function of the typewriter had assumed the form that would become standard in the industry and remain largely unchanged for the next century. Although the machine possessed a cylindrical platen and what was essentially a QWERTY keyboard, two design elements that would later become essential were lacking: the ability to write in upper and lowercase letters and "visible" print. Although the
Typewriter in the Sky of someone else's imagination." Writing in "A Short History of Fantasy" (2009), authors Farah Mendlesohn and Edward James characterized the book as "The best of Hubbard's stories" and noted that it "is better seen as a rationalized fantasy". In a 2009 article on Hubbard's writings, "Booklist" classed "Typewriter in the Sky" and "Fear" as among classics within science fiction and fantasy. Alexei Panshin and Cory Panshin wrote in "The World Beyond the Hill: Science Fiction and the Quest for Transcendence" (1989), ""Typewriter in the Sky" can be understood as an old-fashioned alien exploration story, with a new basis of transfer