Thus, when Burroughs applied the Felt recording principle to his key-set crank-operated adding mechanism, he produced a type of recording machine which proved to be more acceptable from an operative standpoint than the recorder made by Felt; and yet the writer has read testimonials given by those who had both the Felt key-driven recorder and the Burroughs key-set crank-operated recorders, who claimed they could see no advantage. [Illustration] [Illustration: From Drawings of Burroughs’ Patents Nos. 504,963 and 505,078] Probably the best proof lies in the fact that Felt finally abandoned the key-driven feature in his recorders, as may be noted from the later-day “Comptograph.” THE FIRST PRACTICAL BURROUGHS RECORDER The first Burroughs patent to show the successful combination referred to was No. 504,963, applied for May 5, 1892, and issued September 12, 1893. The printing scheme, however, while indicated in the said patent, was applied for in a divisional patent, No. 505,078, issued on the same date. Drawings from both these patents are shown on opposite page. [Sidenote: _Description of first practical Burroughs recorder_] [Illustration: Burroughs Recorder] The new printing device, as will be noted, instead of operating at the bottom of the machine, operates at the rear and prints the paper against a roll mounted outside of the casing. Outside of adopting the Felt method of printing, the general scheme of construction used in the machine of the former-described Burroughs patent was maintained, except that the levers D, used to drag the denominational actuators down, were omitted, and a series of springs, one for each actuator, was supplied to pull such levers down as are released by key-depression when the common actuator drops under crank action. Thus the description previously given will suffice for a general understanding of the mechanical functions of the adding mechanism and the general scheme for the setting up of the type in these later patents. The construction of the type sectors, the printing-hammers and the trigger-latches used to retain the hammers against the action of their operating springs is best shown in the drawings of patent No. 505,078 on page 136. Fig. 1 shows the normal relation, while Fig. 2 illustrates the same mechanism in the act of printing. The type sector as shown in drawings of patent No. 505,078 is marked K, while in the drawings of No. 504,963 it will be found marked 611ᵃ. They are formed from a continuation of the denominational actuators for the total register in the same manner that the type-wheel gear racks h, of the previously described Burroughs patent were formed.