CH. IX] 



UNICURSAL PROBLEMS 



187 



elaborate; but it is an indifferent construction, for it can be 

 described completely by always following the hedge on one 

 side (either the right hand or the left hand), and no node is 

 of an order higher than three. 



Unless at some point the route to the centre forks and 

 subsequently the two forks reunite, forming a loop in which 

 the centre of the maze is situated, the centre can be reached 

 by the rule just given, namely, by following the wall on one 

 side — either on the right hand or on the left hand. No 

 labyrinth is worthy of the name of a puzzle which can be 

 threaded in this way. Assuming that the path forks as 

 described above, the more numerous the nodes and the higher 

 their order the more difficult will be the maze, and the 

 difficulty might be increased considerably by using bridges and 

 tunnels so as to construct a labyrinth in three dimensions. 

 In an ordinary garden and on a small piece of ground, often 

 of an inconvenient shape, it is not easy to make a maze which 

 fulfils these conditions. Here is a plan of one which I put up 



in my own garden on a plot of ground which would not allow 

 of more than 36 by 23 paths, but it will be noticed that none 

 of the nodes are of a high order. 



