136 J. H. Kinahan—Esker or Kam Drift. 
to winding ridges, or a winding or wrinkled structure; thus 
ophiolyte is called serpentine in English on account of its 
structure but in Ireland it is ‘Ca&mstone.” This latter name 
for serpentine is now nearly obsolete, except in parts of Ulster, 
where an impure steatyte with a wrinkled structure is still 
called Camstone. 
Hiscir, pronounced Esker, is a well defined but small ridge. 
A nearly continuous ridge of gravel—Kams—extends from 
Dublin to Galway, dividing Ireland into two nearly equal por- 
tions. This ridge, when Ireland, in the early historic period, 
was divided into two kingdoms, was: taken as the divisional 
line ; and hence the term Hsker has generally been used in that 
country in place of Kam, to-designate the winding or crooked 
ridges of gravels, which in Scotland still retain commonly the 
more correct name of Kam. Although in America the prouun- 
ciation Kam seems some way to have become general, yet, a8 
far as my experience in Scotland goes, the word is generally 
pronounced Kam. 
True Esker or Kim drift comprises more or less winding 0 
crooked ridges and irregular hills of sands and gravels, due to 
the current and eddies generated by the meeting or colliding of 
two or more currents in a mass of water, such as that of a sea 
or large lake. Wind-driftage may also aid ‘in forming esker 
sands, as for instance the long irregular ridges and hills consti 
tuting in many places the dividing ridge between a lagoon an 
a sea, where there is a rise and fall of tide: that is, a colliding of 
two or more currents ;—in a tideless sea the enclosing materials 
of the lagoons are of a quite different nature from Esker or Kam 
There are, both in the United States and the adjoining Cane 
dian prairies, ridges of drift somewhat like the Irish Eskers, but 
at the same time totally different from them. What they are due 
to would be presumptuous in me to say, but they seem to be 
adjuncts of the great glacial moraines, because, as far as I was 
able to study them, they appear to be in connection with the — 
reasts or marginal faces of such accumulations; as if for som* 
