In reply to Alyson:
Don't use an axe, it will get stuck because the wedge is too thin. Go and buy a proper mawl with a hickory handle, NOT fibreglass, and get to work on the logs. It should cost £15 to £20. A mawl (or maul) delivers a heck of a lot of energy and the wide wedge ensures it doesn't get stuck while sending the split log off at quite a good pace; be sure to do it well away from patio doors or plastic drainpipes and wear decent boots. Set the logs end on on a chopping block if you can, or somewhere the head won't be damaged if you miss.
Heft the mawl high overhead with one hand near the head then transfer that hand back to grip the end firmly allowing momentum to do the work as the mawl comes overhead. Straight-grained pieces will separate with a loud bang, quite the most satisfying garden job and the sheer destructiveness allows you to boss your family around and tell them to stand back. The chain saw is up there with the mawl but has the added antisocial element of the noise and the huge amount of sawdust it spews out. As you gain experience you will learn that even a crooked-grained piece like a branch junction can't resist a good hard blow from the mawl, which will split it in a very satisfying way. The key is to hit a facet where the grain is straight, allowing the mawl to penetrate and begin the split, which the wedge forces open.
Edit: hammer and "grenade" will make you deaf with the loud ringing noise it generates and may induce permanent tinnitus - guess how I know this?
Post edited at 15:55