The above cut represents a very cheap and simple gear-cutter. Its principal novelty consists in the use of the large gear-wheel instead of the common graduated table. It is extremely simple, and at the same time possesses all the advantages of the old machine. It will be observed that the crank is connected to the large wheel by a set of intermediate gears, every revolution of which is made to correspond with the number of teeth in the wheel to be cut. This is accomplished by a set of change gears, which accompany the machine. The changes are made in the opposite end of the Crank Shaft. It will be observed that one revolution of the crank bears the same relation to the number of teeth in the large wheel, as one tooth in the wheel to be cut bears to the whole number it is to contain. The number of teeth and the pitch of the wheel is consequently derived from the change gears. When level gears are cut, the head is then set at the proper inclination, and secured by the screw which projects at the rear of the head. The cheapness of this machine more particularly recommends it, the price being but $250, while its efficiency and regular operation are so well established as to require no further comment. [Illustration: =NO. 4.--THE UPRIGHT DRILL.=] This is another admirable engine for diminishing and simplifying human labor. It is applied to the boring of all kinds of iron-work for machinery. The perpendicular drill, as will be readily observed, is worked with a swift, rotatory movement, by means of the bevil gears at its upper extremity. By a wheel--the circumference of which only is displayed in the cut--acting upon the thread of a screw midway its length, it is pressed down upon the piece of work to be drilled. This piece is secured upon a horizontal table placed under the point of the rotary drill, which table may be elevated or depressed at pleasure, by aid of the small lever projecting backward, which acts on a geared wheel playing on the thread of the great perpendicular screw of the main shaft. [Illustration: =NO. 5.--ENGINE LATHE.=] The nature, operation, and application of power in this engine are precisely similar to those shown and explained at No. 2. But it is employed only for the cutting of screws and screw bolts, and the boring of plates, pulleys, etc., which latter operations it performs by aid of Fairmen’s Universal Chuck, which will be described hereafter. In working this lathe, the implement last named is attached to the spindle, immediately under the right hand of the operator. The engine itself is of unusual neatness and finish. [Illustration: =NO. 6.--SMALL POWER PLANER.=] This little engine is similar in action and principle to the cut, No. 1; the iron, to be planed, moving horizontally and longitudinally on a bed, across which the cutting edges move with a downward pressure and a lateral movement, cutting and finishing the surface to the requisite depth and degree, easily and almost to perfection.