Typewriter

Another early issue in the field of the typewriter concerned the relative merits of the type-bar and the type-wheel principles. The latter construction traces its descent through the Burt ma chine of 1829 and the Pratt machine of 1866. In modern ma chines of this variety the types are mounted on a circle or seg ment, the operation of the keys brings each type to correct printing position, and the imprint of type on paper is produced by a trigger action. The type-wheel machines offer an advantage in the ease with which the type seg ments may be changed, thus ex tending the range and versatility of the machine. However, ma chines of this construction have never been very serious competi tors of the type-bar machines in the general commercial field. On nearly all typewriters the print ing is done through an inked rib bon, which is fitted on spools, travels with the operation of the machine, and reverses automati cally when one spool becomes completely unwound, the latter improvement dating from the year 1896.

Following the first shift-key typewriter of 1878, the next great advance was the advent of visible writing. On all of the early type-bar machines the bars were arranged in a circular "basket," located underneath the carriage, and the type printed at a common point on the under side of the cylinder. This con struction compelled the operator to raise the carriage in order to see the writing line. The first visible writing machine appeared in 1883. The earlier visible machines employed the down-stroke principle, the type striking on top of the cylinder. Later the front stroke machines took the lead in the general business field, the first machine of this type to attain prominence dating from 1897. In front-stroke machines the type-bars are placed in a segment in front of the carriage, the type printing on the front of the cylin der. This solved the problem of visible writing and all writing machines of the leading standard makes are of this type.

Recent Developments.

Since the advent of visible writing there have been two other major developments in the general typewriter field, the development of the portable and the noiseless machine. The former—small, light, compact and easily car ried—is especially designed for the owner's personal use. The earliest of these was a small machine of the type-wheel variety.

The first type-bar portable to attain a considerable market ap peared in 1912. Type-bar portable machines of all the leading makes are on the market, and their sale is extending the use of the typewriter to every kind of personal writing. The noise less machine is a front-stroke machine of the type-bar variety, equipped with the usual standard keyboard. It differs, however, from other type-bar machines in that the printing is done not by percussion but by pressure, thus reverting to the principle of the printing press. This is accomplished by means of a little weight on the back of the type-bar. As the type-bar starts, this weight gathers momentum and presses the type against the paper, swiftly and noiselessly. It is too early as yet to predict the future of the noiseless typewriter, but it is obviously growing in popularity.

Form and Tabular Work.

The extension of the uses of the typewriter to form and tabular work of every kind constitutes a distinct and separate development. During the first 25 years of its history, the time-saving service of the typewriter was con fined almost entirely to straight, line-by-line writing, such as letter and manuscript writing, and the like. This limitation was due to the lack of any mechanism for the instantaneous setting of the carriage at any desired writing point. This need, however, was supplied by the decimal tabulator, which appeared in 1898. This device permitted the writing of columns of figures, anywhere on the page and as many as the page would hold, with the same speed as ordinary work. From this improvement the advance to the machine which would add the columns as written was a natural transition. The first adding typewriters added in vertical columns only, but from these in turn have been evolved the complete book keeping or accounting machines, which write and add (or subtract) simultaneously, both vertically and across the page, in any com bination that the work requires. In this field the standard type bar machines, with tabulating and computing mechanisms, have a competitor in the so-called flat-platen machine, which is similar in its combined writing and adding performance, but prints on a flat bed instead of a travelling and revolving cylinder. (See