ALL A MATTER OF BALANCE 267 over. With this in mind our strip was cut into lengths of 2 in, mea- sured with Vernier callipers. It is essential to make a saw guide and use a fine-tooth razor saw. You can expect to waste several lengths before you are sure that the length is true, and even then it is worth checking each length as it is sawn off to make certain nothing has shifted. As with many jobs in a workshop it may well take more time to make the sawing fixture than to cut the actual pieces of wood. Any ragged ends left after sawing can be sanded off, and even here some precautions are necessary. Glue the paper to a flat piece of wood and only sand along the length of the tile before cleaning the end faces. Those with access to a small saw bench have a considerable advantage. To build the model itself a top-down construction is needed. Start with the top pair of tiles and with a thin mixture of wood- working glue fix them together using the Vernier callipers to get the displacements exactly right. It is best to do this on a flat surface using a square to check they are in line on their sides. Cross out this step on your pre-prepared table of displacements