ABSTRACT
What are coordinate-motion puzzles? For illustration, a simple amusement consisting of three identical rhombic blocks with pins and holes is shown in Figure 139. Note that the only way it can be assembled is to start all three pins into the holes simultaneously and bring all three blocks together. This model is a simple example of coordinate motion. Such amusements cannot be assembled sequentially, but rather at some stage of assembly they require the simultaneous manipulation of three or more pieces or groups of pieces. Unlike this simple example, such puzzles can be very baffl ing. One such puzzle has already been included surreptitiously in a previous chapter without being identifi ed as such!
