History of the Typewriter

—273— from the left edge of the sheet, for the beginning of the next line, the adjustment of the margin to any width desired being quickly made, and as quickly changed. The ribbon feeds automatically, and is vertically disposed across the front of the platen, and as it is very narrow, only the line being typewritten is concealed thereby, all the preceding lines being always distinctly visible. The platen-supporting slide is movably supported on a central vertical shaft, and at any time can be depressed by hand thereon, if it is desirable to lower it, but the entire action of the machine is automatic, and by depressing an arm, and thereby forcing the platen-supporting slide from engagement with the dogs which ordinarily raise the platen, tooth by tooth, for each line, the slide carrying the platen will be instantly raised its full height, so as to be in position to remove the sheet of paper therefrom, or place a fresh sheet thereon, after which the platen can be quickly depressed to its initial position. DIAGRAM SHOWING THE ACTION OF THE TYPEWRITER Fig. 198. The actuating mechanism for vertically moving or horizontally revolving the platen comprises independent spring mechanism and suitable connections, there being two drums, with volute springs therein adapted to revolve said drums in opposite directions, the described line-key being connected with one of said drums for automatically raising the platen, without rotating the same, and the margin-regulating key being connected to the other drum for automatically revolving the platen, without varying its elevation, by the mere act of depression of one or the other of the said keys. Further, each time the last-named key is