History of the Typewriter

— 74 — The paper fingers are very effective, and grip wide or narrow paper well. The card platen and marginal stops are also very good features, and it is claimed that the models of the Densmore in use to-day include every device which has been found practicable either to increase the range of typewriters, or reduce the labour of the operator- Group II.—Machines with full keyboards. The Caligraph. We have already (page 46) referred to the introduction of the machine now under notice. A double keyboard having been decided upon, the next step was to secure the improvement in the carriage, for even in those early days it was seen that lightness was an essential precedent to speed. An entirely new model of carriage was there- fore provided, and so light was it, that ultimately the lifting weight was only about eight ounces. It will be noticed, on reference to the illustration, that the front portion of the Caligraph is occupied by a sloping desk upon which the operator might easily support his arms. The object of this desk, however, was no such humani- tarian idea, but to enable the levers to be lengthened in front, and the fulcrum was placed towards the operator instead of from him. A lever so constructed is known mechanically as one of the second order of leverage, and as we shall see in this section, it is interesting to find, long after the Caligraph was withdrawn from the market, that the same idea was incorporated in another machine—the No. 10 Yost to wit. So light was the leverage which resulted, that the keys required a depression of not more than Ifths of an inch in order to bring the types to the printing point. The mechanism governing the movement of the carriage was altogether different to that of the Remington. Instead of a coiled spring in a drum pulling a strap attached to the further end of the carriage, we find in the Caligraph a long spiral spring mounted on an iron bar, and passing from front to back of the machine under- neath the key-levers. This spring, which could be adjusted to a remarkable degree of fineness, was attached to a long driver arm at the rear of the machine, and the arm, in its turn, was attached to the carriage. The result was that a far more uniform movement of the carriage was secured, for it must be quite clear that the tension