to Blickensderfer's typewheel was introduced on the Crandall 1 typewriter in 1883 but Blickensderfer's genius was in the use of the typewheel combined with the simplicity and the small size of his machine. This invention was unlike anything else on the market and was considered a mechanical marvel that took typewriter engineering to a new level. Striking a key turned the wheel to the appropriate orientation while inking the typeface as it tipped downward past the ink roller to strike the paper. Holding the Cap or Fig keys shifted the typewheel along its axis to use either the middle row, for capital letters, or the lower row, for special characters and numbers. Industrial production in the 1890s was not highly automated and assembly was done completely by hand. This allowed for easy design changes and improvements to the production process. Blickensderfer continued to improve his machines and a number of new patents were filed for the Blickensderfer 5 up to June 1, 1897, when the machine largely remained the same for the balance of its production life. Blickensderfer continued to invent new machines until his death, including the Blickensderfer Electric and various standard machines with the Blickensderfer 9 being his last major new model. The typewheel, like the later typeball of the IBM Selectric typewriter, was the central component of all the Blickensderfer machines. It could be easily removed, allowing users to select a large variety of fonts and typefaces. Later in the company’s production history the basic machines' keyboards could easily be adapted to other languages at the Blickensderfer factory simply by changing the removable keytop covers and adding the corresponding language typewheel. Scientific keyboard One unique feature of the Blickensderfer typewriter was the scientific or DHIATENSOR keyboard. The DHIATENSOR layout is shown below (with alphanumeric characters only): Blickensderfer analyzed the English language and proposed a unique and more efficient keyboard based on his research. He determined that the ten most frequently used letters were A, D, E, H, I, N, O, R, S, and T and were used in about 70% of written text and in about 85% of all words. The middle row contained letters that occurred 24% of the time and the top row about 6%. Blickensderfer offered the scientific keyboard in the hopes that his more efficient system would replace the clumsy but widely used QWERTY or universal keyboard developed by Sholes and Glidden in