Chestnuts have twice the starch content as potatoes and are used as a potato substitute in some parts of the world.
In the next few minutes you will see how easy it is to graft apple trees. This illustration shows the whip and tongue graft which is the simplest and most reliable type of grafting for apple as well as other fruit trees. You will need a few specialized tools that were outlined in the Grafting Fruit Trees article. Find a flat surface to lay out your grafting tools and supplies. The picture above shows everything you will need. These include from top to bottom, L-R, Doc Farwell's Grafting seal, a cup of water, electrical tape (can use masking tape and rubber band too), scion, metal tree tag and green wire to affix tag with, apple rootstock, hand pruners, grafting knife, wood blocks, cardboard hand protecter (this is key to keep your fingers intact!).
Cut the scion so that there are 2-3 buds, be sure that the top cut is just above and angled away from the top bud (left most). Leave as much room below the bottom (right most) bud as possible.
Cut a ~30 degree angle below the and on the side opposite the bottom bud.
In the picture below you can see the thin dark green cambium layer. This is what we want to keep in contact between the rootstock and scion.The next step is to make the tongue. To do this use the cardboard finger protector and make a cut on the flat side of the previous cut from the bottom toward the top of the scion, total length of this cut is between 1/4" and 1/2". To make a flat cut it helps to raise the scion up a few inches from the larger surface you are working on.
Here we can see what a properly cut tongue looks like.
Once the scion has been cut we select a similarly sized area on the rootstock to prepare for grafting. This is done with the same cuts as on the scion.
Here we see the scion and rootstock together. Each has been cut with a tongue and they are ready to slide together. Notice that the width of each cut is very similar, this helps to have maximum cambium contact.
Next we face the cut surfaces of the rootstock and scion, then slide them together so that the tongues interlock.
The farther they are slid together the tougher it will become. Don't push too hard but you should feel how tight they fit together. Make sure that the cambium is matched as best you can. You can get an estimate by lining up the rind on both sides. This is what it will look like when rootstock and scion are properly fit together and ready for taping.
The next step is to tape the graft together. For this it is best to start on the rootstock, get the tape established and then wrap up toward the scion. It is a good idea to slightly stretch the electrical tape each time you wrap the main part of the graft, this will help the cambium stay in contact.
The next thing to do is paint the tape as well as the tip of the scion with grafting seal. This picture shows Doc Farwell's but use whatever is available to you.
At last, you have a properly grafted and sealed apple tree, complete with appropriately labeled tree tag. Plant this in your garden or orchard and keep it well watered, especially during the first growing season.
To read more about the principles of grafting see this overview of Grafting Fruit Trees.