There are two distinct types of machines, the cylinder machine and the flat-bed machine. A well-known machine of the cylinder type is shown in Fig. 26. The machine has two cylinders, one for type storage and one for printing. The type is held in slots in which it moves freely. To set up a letter on the printing cylinder, the storage cylinder is revolved until the pointer at the top of the machine reaches the desired letter, when a slight pressure of the finger on the small lever in the center moves the type into the slot on the printing cylinder. This is continued until the line is set, when the printing cylinder is moved into position for the next line. To distribute the type to the storage cylinder, this operation is reversed. After the letter is set, a ribbon is drawn around the printing cylinder, and the machine is ready to print. The paper is fed, printing side up, underneath the cylinder. A turn of the crank draws the paper through, prints it, and discharges it at the back of the machine. Special power attachments can be put on which operate both the machine itself and an automatic feed, which greatly increases the speed. [Illustration: Fig. 28. The Writerpress Printing Machine. _The Writerpress Co._] Machines of the flat-bed type are shown in Figs. 27 and 28. With these machines the type is kept in cases, the compartments of which are arranged in the same order as the keys on a typewriter. The type is set up and locked in a chase, just as it is by a printer, and the chase placed on the flat bed of the machine. The ribbon is stretched tightly over the type, the printing being done by moving an impression roller over the ribbon. Paper is fed, one sheet at a time, against the paper guide, and the roller, passing over, produces the desired printing impression. When the roller is returned, the sheet is automatically ejected and counted. The pressure and shade of the printing are regulated by the adjustment of impression screws. An advantage claimed for this type of machine is that electrotypes and zinc etchings can be used, or regular printers' job type can be substituted for printing small circulars and office forms. If a letter or form is used frequently, it can be electrotyped and held permanently, releasing the type. [Illustration: A WELL-ARRANGED OFFICE OF A BANKING HOUSE Peabody, Houghteling & Co., Chicago, Ill.] REVIEW QUESTIONS. PRACTICAL TEST QUESTIONS. In the foregoing sections of this Cyclopedia numerous illustrative examples are worked out in detail in order to show the application of the various methods and principles. Accompanying these are examples for practice which will aid the reader in fixing the principles in mind.