A visit to the Curtiss factory is of interest to any one interested in machinery and there you will see the latest machines of all types, from powerful milling machines to a delicate modern "Printograph" that is almost human in its manner of getting out letters and printing, for it is a cross between a printing press and a typewriter. Another unique machine is one that carves out propellers from a laminated block of wood. One arm of this machine runs over a model, and the other, about two feet away, arranged to move exactly with it, and provided with a tool of cutting edge, forms the propeller blade with absolute accuracy, out of a block of wood placed parallel to the model. The cutting tool follows all the complex changes in the surface of the wooden propeller with the greatest ease and rapidity. The brazing room, where the oxy-hydrogen torch is used to braze metal parts together, and the room where they weld the water jackets on to the cylinders, are places of special interest; the nickel plating room, japanning room, and the room where painting and drying are done, almost complete the tour of the various departments, but there still remain the wood-working shop, boat shop, assembling rooms, where the aeroplanes are put together and completely set up, and the motor testing room, where motors are run for whole days, ten hours at a time, driving an air propeller and showing on scales the amount of thrust given at all times. Here you may also see a machine to make "brake tests" of the motors, by which is told how much horse-power the motors give. This machine consists of a large drum with a brake fixed against it and cooled by water so it will not get too hot. This brake absorbs the energy of the motor, which is measured by an arrangement of scales and lever arms. There is a tremendous racket when the big motors are running at full speed in this small room, and the hillside rings with the roar of their fiery exhaust.