In Fig. 36, is shown the successive movements and events determined by the sleeve, and the method of opening and closing the inlet and exhaust ports by the elliptical movement of the sleeve. The shaded ports are one of the inlet and one of the outlet ports, respectively, which are cast in the cylinder wall, and are afterwards machined true. The dotted port, which changes its position in each diagram, is one of the ports in the moving sleeve, its position in each of the figures is marked by the event that is occurring in the cylinder at that time. In diagram 1, the shaded port to the right is the exhaust port, and the shaded port to the left, the inlet, this relative arrangement being true, of course, in each of the succeeding diagrams. It will be noted, that in the position shown, in the exhaust stroke (beginning of stroke), the sleeve port has just started on its downward stroke, moving also a trifle to the right as it progresses. Its progress to the right may be more clearly seen by consulting diagram 2, for the movement. By consulting the other five figures it will be seen that the dotted port, in its relation to the shaded ports, first moves out to the right, and then reverses, moving to the left, and this combined with the up and down movement constitutes an elliptical path. In diagram 6 the exhaust is closed, and the inlet port has just begun to open, the dotted port now starting to move out to the left, and to rise. [Illustration: Fig. 35. Elevation of Argyll Single Sleeve Motor from The Motor, London. ] In diagram 10, the inlet is nearly closed, the sleeve port passing away from the cylinder ports to the water jacketed portion of the cylinder above. [Illustration: Fig. 36. Valve Motion Diagram of Argyll Motor Showing the Valve Positions at Different Parts of the Working Stroke. ]