Monotype keyboards. The machine at the left is a "DD" or double keyboard equipped with two paper ribbons Monotype casting machines. These are operated by electric motors, but the mechanism is controlled by compressed air Hand composition room. Here electric power is a small factor, the work being performed in much the same manner as in Gutenberg's day perforations the keyboard operator made, those that determine the width of the spaces between the words in the line, are the first presented to the casting machine. These adjust the machine to produce spaces of the proper width, after which the letters are cast in the required order. The foregoing description applies only to the ordinary Monotype keyboard, known as the single or "D" board. In many printing offices this has been superseded by a double keyboard, called the style "DD." This is identical with the single board, except that it is equipped with two paper ribbons, as well as the mechanisms that operate them. Striking any key on the keyboard causes perforations to be made in both ribbons of paper, or by the movement of a small switch either ribbon can be disconnected from the keys so that the perforations are made only in one of the ribbons. The "DD" keyboard has increased greatly the usefulness of the Monotype. Assume that the copy to be put in type is a novel that is first to be printed in small type, two columns to the page, for use in a magazine like Harper's or Scribner's. Afterward the novel is to appear in book form, one column to the page, and in larger type. The operator moves the switch so both paper ribbons are in operation, and proceeds to compose or "keyboard" the copy. Every key the operator strikes makes perforations in both ribbons. One of the ribbons, when fed through the casting machine, produces small type set in a narrow measure. The product of the other ribbon is the same copy set in large type and of a wider measure. Thus, it will be noted, one operation at the keyboard produces at the casting machine two entirely different products. Assume that the copy consists of alternate paragraphs of large and small type, such as a dictionary, or that these alternate paragraphs are to be set in Roman and German type. The operator moves the switch to the right, locking out the right paper ribbon, and sets up the first paragraph. The switch is then moved to the left, bringing the right hand ribbon into commission and locking out the other, and the next paragraph is composed. The two different ribbons are then fed through the casting machine and the product assembled in proper order. The operation of the Monotype casting machine (shown on plate II) is entirely automatic, after having been adjusted and started, requiring no further attention except that the |