A boy's text book on gas engines

by Fay Leone Faurote

Fig. 4—A Four-cycle Diagram, showing sequence of strokes in this type of motor.

This does not mean very much to you, does it? Well, let us go into it a little farther. Supposing you were running relay races around a block; you would run down on one side, across on another, back on the other side, and then back to the starting point, wouldn’t you? You would have completed a cycle then because you have taken a “certain time in which a succession of events (streets) has been completed” and you are back again at the start ready to “return in the same order.”

Fig. 5—Drawing showing comparison between gas engine and a cannon connected with a grindstone.

There is not anything complicated about that, is there? In other words just change the four-stroke cycle to a four-street circle, and this will help you to keep in mind the meaning of this term. Do you remember last Fourth of July when you had your cannon out, how many things you had to do to fire it, or in other words to complete the cycle of operations. You did four things, didn’t you?

No. 1. You put in the powder.
No. 2. You rammed it in with a ramrod.
No. 3. You fired it by touching a match to it.
No. 4. You cleaned it out.

You had gone around your four-sided circle, and were back again, at the start, ready to do the same things over again. You were running a gas engine then, only you did not realize it.

Let us assume for the sake of argument, that you had a bullet in your cannon, and that to this bullet was connected a rod which had its other end fastened to the crank of a grindstone. Then if the barrel of the cannon was long enough, and the rod which connected the bullet and crank was short, the bullet could not get out of the cannon barrel, could it? It would therefore have to go back and forth very much like the pedal on a grindstone does. Of course the rod and the crank would have to be very strong in order to keep the bullet in, but we will assume that they are, and that the bullet must travel back and forth inside the barrel. Now, if the bullet is going to stay in the barrel we must provide some way to load the cannon, and also to clean it out, therefore we will cut two holes in the end, one at I and one at E, and then instead of using powder suppose you use some explosive gas which will not leave so much soot behind it. You know how a squirt gun works—how you draw the water in by pulling out the plunger, and how you force the water out again by pushing it in again.

Fig. 6.