The decimal tabulator is a notable example of how one idea leads to another. During the years immediately preceding its appearance there had been happenings in other branches of the office appliance field. The idea of clerical labor saving, embodied in the first typewriter, had given birth to a varied industry, and among other new inventions, had produced the adding machine. The first adding machines, however, carried no printing mechanism, and so long as typewriters were also lacking in a tabulating mechanism, the fields of the two machines lay entirely apart. In the early nineties, however, the Burroughs machine, which listed figures in a column as added, began to find a market. Soon after came the first tabulating typewriter, and it was soon recognized that each of these machines represented a partial approach to the field of the other. The question then arose: "Since the typewriter now writes figures in columns, why not build one that will add these columns as written? In other words, why not build an adding typewriter?" In due time the adding typewriter came, to be followed later by the typewriter-accounting or bookkeeping machine. Prominent among machines of this type are the Elliott-Fisher, which has a flat writing bed or platen, the Remington, which introduced the feature of automatic subtraction, and the Underwood, which is electrically operated. The earlier adding typewriters added in vertical columns only, but soon a cross-adding mechanism was added, and the two acts of vertical and cross computation are performed in one operation. The accounting machine completed the application of the typewriter to every form of business writing, including combined writing and adding. In the latter field the advantages it offers are those of the typewriter intensified. The combination of two tasks--writing and adding--in one, eliminates the separate adding and the separate adding cost. A further advantage is the error-proofing of every task, the machine furnishing its own checks against possible mistakes by the operator. To the business man these advantages are decisive. The typewritten bill is now about as universal as the typewritten letter, so also is the typewritten statement, and the old-fashioned bound and pen-written ledgers are fast giving place to the modern card ledger, kept on the bookkeeping machine. The same applies to every conceivable kind of combined typing and adding in every line of business. The pen has not entirely disappeared from these fields as yet, but it is going, and its final departure is as clearly indicated as anything in the book of fate.