DISCOVERY OF THE PILTDOWN SKULL 295 
searched the gravels of his own locality, and soon found 
implements of the same types as M. Boucher de Perthes 
had found in the deposits laid down in former times by 
the Somme. Mr Harrison, however, carried the history 
of flints a great stride further back. Little more than a 
mile north of Ightham rises up the chalky bank of the 
North Downs which forms the northern lip of the 
Wealden cup. Crossing the Pilgrims' Road, which winds 
along the foot of the bank or escarpment, Mr Harrison 
had,"in his almost daily excursions, a stiff upward climb 
of some 500 feet to reach the plateau of the North 
Downs, stretching away northwards into the valley of 
the Thames. Here, in the gravel deposits of the plateau, 
immensely older than the terrace gravels of the valleys, 
Mr Harrison found rudely shaped flints, which he 
recoo;nised as being of human workmanship. They were 
prirnitive in form when compared with the palaeoliths 
from the valley gravels, and he distinguished them as 
"eoliths." Although he recognised them first in 1865 
— forty-eight years ago — eoliths were not accepted as 
genuine products of man's hand until 1888, when the 
late Sir Joseph Prestwich — a geologist noted for his sound 
judgment — brought them before the scientific world. 
Even when Mr Dawson began his researches in the 
Weald twenty years ago, eoliths, although gradually 
gaining adherents, were still the subject of hot contention. 
It was about this period, too — the end of last century — 
that a great truth, the inception of which we owe to our 
colleagues of France, began to leaven the researches of 
the Wealden workers. This truth is simply the recog- 
nition that the law of change or progress, which influences 
all the worldly afi^airs of men, holds true not only of 
present but also of past generations of mankind. Every 
generation has its own distinctive fashions and ideas ; it 
builds its houses, it tills its fields, it makes its implements, 
it writes its books, it wears its clothes and paints its 
pictures in a manner slightly different to the generation 
which went before it. It is not diflicult to distinguish a 
house built in the time of Queen Elizabeth from one 
