History of the Typewriter

—259— framework, while in front of the same the keys are disposed in the usual step-shaped manner. The keys, arranged according to frequency and convenience of use, are connected by downward descending wire rods with a corresponding number of parallel levers that are fulcrumed to cross pivots of the frame and extended backward, carrying at their rear ends the type-rods, which are curved in an upward and inward direction toward a common centre, being guided by suitable guide-plates. As the type- operating levers are arranged to pass below a vibrating pawl-operating bar, the depression of each key produces the action of the double pawl. The spaces between the words are formed by the depression of a space bar. The paper is fed forward for the space required between the lines by means of two feed rollers, of which one is placed above the other, journaled to suitable supports of the carriage, and which act automatically with the same. The shaft of the lower roller is provided with a ratchet wheel and check pawl to prevent backward motion. The shaft of the lower roller is provided with a spur wheel whose radially extending and equidistant teeth are engaged by the free end of a band-spring that is affixed at one end to the frame of the machine, and so twisted or shaped that it presses against one of the spokes when the carriage is drawn back, turning thereby the spur wheel and the feed rollers to the distance required between the lines. This spring may be further arranged to strike a bell when releasing the adjoining spur of the wheel, in order to indicate the approaching end of the travel of the carriage. The carriage is also provided with an indicating pointer running along a graduated scale at the front part of the casing, to enable the operator to see at any time the distance to which the line is printed and when it is completed. American. The U.S. name of the Armstrong. Automatic. This was a type-bar machine of the first constructive group. There were forty-eight keys, for capitals, figures, etc.; the dimensions of the machine were n| by 8} by 4 inches, its weight being about ten lbs. It possessed one or two very curious features, one of them being that the space bar was behind the keys, this being enough to kill the machine of itself. The types struck upwards from the centre of the machine, each type travelling only about one inch from the point of rest to the printing point. No ribbon was used, the type receiving their ink from a pad of felt against which they were held by pressure of a spring. The pad could be changed very quickly. _________