It would be misleading of me to represent the stages summarily sketched above as being either continuous or consecutive There have been periods of retrogression or stagnation broken by others of rapid development during which outmoded ideas have held their place beside the new Again cartographers have constantly realised the theoretical basis for progress but have had to wait for technical improvement in their instruments before they could apply their new ideas Since the easiest way to make a map is to copy an old one and considerable capital has often been locked up in printing places or stock map publishers have often been resistant to new ideas Consequently maps must never be accepted uncritically as evidence of contemporary knowledge and technique 