T. V. Holmes—On Eskers or Kames. 443 
latter country. In addition to my trust in his statements as those 
of a good and careful observer, I have the more confidence that the 
ridges he has described to me are true eskers and not merely curious 
effects of circumdenudation, from the fact that his attention had been 
drawn to the subject just before visiting them by the perusal of a 
paper on eskers by the late Dr. Robert Chambers. The first esker 
district to be described is that between the port of Pisco and the 
town of Yea, in Peru. The eskers stand on a plain of marine 
denudation, which has a very gentle slope from the mountains to 
the sea, extends from the north of Peru to the borders of Chili, and 
is known as the desert of Atacama. They consist of high ridges 
and mounds of shingle mixed with sand. Mr. Winder remarks :— 
«‘That they are true eskers can hardly be doubted, as in some places 
where sections exist the shingle is clearly to be seen heaped up as 
though by the force of opposing currents.” These ridges have a 
general east and west direction, and the roads or bridle paths to the 
interior usually run along their tops, crossing from one to another 
when necessary. As the ridges tend to converge towards the 
mountains and to diverge from each other towards the coast, the 
traveller towards the interior does not cross from one to another till 
he has arrived at a considerable distance from the shore. The reason 
for having the roads on the tops of the ridges is not merely the 
advantage of a better view, but the superior firmness of the ground. 
The district is almost perfectly rainless, and the only streams 
running through it result from a periodical melting of the snow 
on the mountains, and are dry most of the year. The only subaerial 
denuding power is that of the prevailing southerly winds which 
blow a considerable amount of sand from the esker ridges into the 
spaces between them. Consequently the ground between the ridges 
is so soft as to offer almost insurmountable obstacles to man and 
beast where more than a very short distance has to be traversed. 
These esker ridges sometimes rise to a height of more than 200 feet 
above the plain on which they lie. 
Another district in which Mr. Winder has noted eskers is that 
between Cobija and Calama, a few miles south of the boundary 
between the coast of Peru and that of Bolivia. Here the shore 
is not low as about Pisco, but bold and rocky. The path from the 
coast-town of Cobija towards Calama is through a rocky gorge 
beginning about five miles from the port. After ascending this 
gorge about twelve miles, the traveller finds himself 2000 feet 
higher than he was at the other end of it, and emerges into open 
ground which has the appearance of a recently elevated sea-bottom. 
In two respects the eskers of this district differ from those of the 
other; they are much smaller, and their general direction is not 
east and west, but north and south. They are also much closer 
together. Travelling eastward is rendered much more laborious 
here than in the northern district through the unfavourable direction 
taken by the ridges. ‘It is very difficult,’ Mr. Winder remarks, 
“to give any general description of the district, as it is simply a 
desert in which there is often a distance taking two days’ hard 
