As this has been already mentioned, it is only necessary to say that it can be obtained ready made, with several holes for different thicknesses of dowels. Bits, of course, will be required to match.
There are several other appliances which, if not absolutely necessary, are at any rate so useful, that they should be added to the outfit as opportunity occurs. Many of them being of wood may easily be made by the user, though, if he is a novice, he will find it difficult to do so in some instances. Should he not be able to manage by himself, he can easily get any experienced wood-worker to do what is necessary, and sufficient instructions will be found in the next chapter.