Page:Motors and motor-driving (1902).djvu/164

without particular reference to the diagram, the cycle is laid out as follows:

First Cylinder ⁠	Second Cylinder
⁠Suction	⁠Exhaust
⁠Compression	⁠Suction
⁠Firing	⁠Compression
⁠Exhaust	⁠Firing

From the above it will be seen that one working stroke immediately follows the other, so that an even impulse is

Fig. 20

obtained once in every two revolutions of the crank shaft, the other revolution being non-effective.

The second diagram, fig. 20, explains the cycle of events in the cylinder when the cranks are set at an angle of 360 degrees. It will be noticed that the two pistons i, i, are both about to commence a downward stroke, and that they consequently work together instead of opposite to each other, as in the