History of the Typewriter

—187— Fig. 140. in full view of the operator, thus bringing every character into sight, from date to signature. The type-bar of the machine is interesting. Its lower encl, or, rather, the end furthest away from the operator, passes through the openings in a curved steel comb-like segment. The flat type-bar works freely and easily between these openings on its way to the printing point, where it meets a guide or alignment lock. In this way, not only perfect but permanent alignment is secured. There is also a supplementary virtue in a type-guide or lock, namely, that should two keys be struck simultaneously neither of them can enter the guide, and false imprints are quite impossible. The segment referred to is fitted with a pro- jection at the back and front of the machine to catch the dust caused by erasing and prevent it from going into the type-bar bearings ; also with a ring against which each type strikes as it reaches the cylinder, thereby causing uniformity of impression as well as saving the wear of the cylinder. The touch of the Underwood is an agreeably light one, for which the reason is simple. In practically every machine the difficulty of touch is caused by the universal bar, which is held in close contact with the type-levers, so that when a. key is depressed the force required is not only what