To specify a method for facilitating installation and adjustment of two pipes.

To provide a simplified method facilitating installation of an amusement instrument including piping structure regularly installed on a base by using a method for facilitating adjustment in a lengthwise direction of a groove related to the base. The method includes a pipe piece 2 extending in a pipe 1, and the pipe piece is regularly installed in the base. The pipe piece is provided with a folding in the lengthwise direction in order to form grooves 4 opening outward. Wedge elements 3 are inserted in these grooves 4, and bolts 4 passing through the pipe 1 tightens the wedge elements. The pipe piece 2 is then expanded because of the sectioned shape of the groove and is squeezed against the inside of the pipe 1. Thus, the pipe can be adjusted in regard to installation and subsequent adjustment.