History of the Typewriter

— 96 — Fig. 75 point, where they enter a type-guide, which thus secures alignment. There are twenty-seven keys working with two shifts, so that eighty-one characters are provided, and the inking is effected by a ribbon. The type-bar is the great part of the machine, and is well worth examination. Just at the rear of the type button is what is technically called a saddle. Inside this saddle is a slight indentation or cup, and this cup fits on a post in the base plate of the machine, being held there by a spiral spring. The result is an entire absence of friction so that a very light touch is sufficient to secure an imprint. The Armstrong is fitted with marginal stops, but no margin release. The carriage runs on ball bearings, and is geared direct on to the drum of the mainspring, and being centre-driven, there is the same tension at the end of the line as at the commencement. The escapement is a star- wheel arrangement, and is capable of responding with the utmost rapidity. The usual means for sounding the warning bell, reversing the ribbon, etc. are provided. The line spacing is made simultaneously with the return of the carriage, and several carbon copies can be made at one operation. The Armstrong is also a good stencilling machine. Fig. 76