Since the general installation of the recording-adder by the banks, the minds of “get-rich-quick” inventors have been turned toward this type of machine. The result has been that a vast number of patents on such machines were issued, a large proportion of which represent worthless and impossible mechanism purported by their inventors to contain improvements on the Art. Some of these patents on alleged improvements describe and purport to contain features, that, if really made operative in an operative machine, would be useful to the public. But as inventions, they merely illustrate the conceptions of a new and useful feature that can never be of use to anyone until put into concrete operative form. To describe these features would be useless, as they have not advanced the Art; they merely act to retard its advancement through the patent rights that are granted on the hatched-up inoperative devices or mechanism purported to hold such features. [Sidenote: _But few of the recorder patents of value_] Of the vast number of patents issued, but few of the machines represented therein have ever reached the market, and of these machines, except those previously mentioned, there is little that may be said respecting new elementary features that may be called an advancement of the Art. It is to be expected, of course, that the manufacturer of such machines will not hold the same opinion as the writer on this subject. But the fact that the generic principles of recording the items and totals were worked out before they even thought of constructing such a machine leaves little chance for anything but specific features of construction for them to make that may be considered new. [Sidenote: _Reserve invention as good insurance_] Another feature to be considered in this line is that while these new manufacturers were working out the “kinks” or fine adjustments, which can only be determined after a considerable number of machines have been put into service, the older manufacturers were working or had worked out and held in reserve new improvements that were not obvious to those new at the game. It is quite common for manufacturers to have a reserved stock of improved features to draw from. In fact, such a stock is sometimes the best insurance they have against being run out of business by a competitor who places a machine on the market to undersell them. Of course, all manufacturers believe they purvey the best and advise the public relative to this point in their advertisements. [Sidenote: _Erroneous advertising_] One manufacturer of a recording-adder, a much later invention than either the Felt or Burroughs recorder, circulated some advertising pamphlets once which contained a statement that their machine was the first visible recorder. A reproduction of this pamphlet is shown on the opposite page. The reader will at once recognize the error in such a statement, as the first Felt recorder was a visible printer.