The pistons are of the Swedish type, of hollow iron, with steel rods. The segments are of cast iron. The horizontal connecting rod, M', is connected directly with the crank pin, _m_, but the vertical one is fixed to the head of the former, as may be seen in Figs. 3, 8, and 9. The bearing of the horizontal connecting rod is in three parts, each having an anti-frictional bushing, and their play being regulated by bolts, _m²_. Friction being slight in the bearing of the vertical rod, M, inasmuch as the latter's axis has but a short travel at each revolution of the driving shaft, it is not provided with an anti-frictional bushing. _The Small Cylinder_ (Figs. 5 and 6).--The small cylinder is shown in detail in Figs. 5 and 6, the valve box cover being removed in the latter. The diameter of this cylinder is 380 millimeters, the stroke of the piston is 650 millimeters, and the thickness of the sides is 25 millimeters. It is provided with a steam jacket; and the two ports are 45 millimeters in width by 200 in length. The exhaust is effected through an orifice 84 millimeters in diameter. The distribution is a variable one, according to the Meyer system, the expansion being caused to vary automatically in the small cylinder, by means of a regulator, so as to proportion the motive to the resistant power. The distributing slide valve, _t_, contains two steam inlets, whose orifices facing the cylinder are formed by two horizontal, parallel rectangles, while the inlets debouch toward the opposite surface (in contact, consequently, with the expansion slide valve, _t'_), according to two parallelograms, whose larger sides are oblique, and form between them a sharp angle, as may be seen in Fig. 6. These inlet conduits are therefore out of true. The slide-valve, _t_, is moved by an eccentric, E. The expansion slide-valve, _t'_, has the form of a trapezium, whose two like sides are parallel with the inclined openings in the slide-valve, _t_. It is held by a piece, _q_, which carries it along in its backward and forward motion, but does not prevent it from being moved in a horizontal direction under the action of the regulator. This piece, _q_, is keyed upon a rod, _q'_, which is itself jointed at its lower extremity with the rod, _e'_, of a second eccentric, E', which causes its vertical motion. The backs of the valve, _t_, and the piece, _q_, are provided with grooves, which are designed for giving passage to the steam, the pressure of which on these surfaces partially balances that that it exerts in an opposite direction.