The mechanism of the roller copier is shown in Fig. 4. The paper from the roll is passed under the dampening roll in the water tank, then between the large roller and the wringing roller, over the same large roller and between it and the copying roller, thence out over the flanged roller and down to the winding reel. The pressure on the wringing and copying roller is adjusted by the adjusting screws _A_ and _B_, and the adjustment lever throws the pressure on or off. The letter to be copied is laid face down on the feeding shelf, the edge is placed under the copying roller, pressure thrown on, and a turn of the crank carries the letter through into a receiving basket, leaving a perfect copy. If additional copies are wanted--any number up to a half-dozen--the operation is repeated for each copy. [Illustration: Fig. 5. General View of the Yawman & Erbe Roller Copier] The paper on which the copies have been made passes to a winding reel under the copier, as shown in Fig. 5. This is a large rectangular reel on which the paper is stretched tightly, so that it will be smooth when dry. The open construction of the reel affords free circulation of air, drying the copies very quickly. After the day's copying is done, the action of the machine is reversed by the turn of a thumbscrew, the paper is broken above the last copy, that on the reel is brought back over the copier, and the letters cut apart with the cutting knife at the end of the feeding shelf. The separate copies are then ready for filing with the original letters, keeping letters and replies together. Among the advantages claimed for the machine are certainty of legible copies, copies of all corrections, and economy of operation. The copies are made after the letter has been written and corrected; consequently it must be a facsimile. If a note is written at the bottom or on the margin, it is shown in the copy. Copying is the last operation before mailing. Frequently a man finds, after the letter is written, that he needs additional copies. With the carbon system it is necessary to rewrite the letter; with the copier, the copies can be obtained any time before the letter is mailed. The copier is economical in operation. The best quality of paper costs 50 cents a roll, and a little more than one roll, or about 60 cents' worth of paper is required for 1,000 copies; and there is no carbon paper to buy. The office boy can operate the copier, and it takes but a few minutes to copy the day's mail of the average concern. If desired, the machine can be obtained with an electric motor attached, but this power is really unnecessary unless the correspondence averages 300 or more letters a day. STENOGRAPHIC DIVISION