Y is for Frances Yates (1899 – 1981) whose book the Art of memory uncovers the history of the  technique used from 5th Century BC in classical Greece until the between the 14th and 17th Century  during Renaissance  to commit quantities of information to memory.  This was a vital skill before paper and printing and the written word replaced the memory for the storage of rote information.  In her book Frances Yates describes the ‘workings’ of the system in detail.

First we understand the  general principles of the mnemonic, then, it is necessary to imprint on the memory a series of loci or places,  before the images by which the speech is to be memorised in the various ‘buildings’.  After this as soon as the memory of the facts needs to revived, all the places are visited in turn and the various ‘deposits demanded of their custodians’.  

We can think of the ancient orator was walking in imagination through his memory palace or building, while he is making his speak,drawing from the memorised and the images he has placed in them.  

The method ensures that the points are remembered in the right order, since the order is fixed by the sequence of places in the buildings or landscape.