402 A JOURNEY IN BRAZIL. 
merged. To this I can only answer that, in the State 
of Maine, I have followed, compass in hand, the same 
set of furrows, running from north to south in one un- 
varying line, over a surface of one hundred and thirty 
miles, from the Katahdin Iron Range to the sea-shore.* 
These furrows follow all the inequalities of the country, 
ascending ranges of hills varying from twelve to fifteen 
hundred feet in height, and descending into the inter- 
vening valleys only two or three hundred feet ahove the 
sea, or sometimes even on a level with it. I take it to 
be impossible that a floating mass of ice should travel 
onward in one rectilinear direction, turning neither to 
the right nor to the left, for such a distance. Equally 
impossible would it be for a detached mass of ice, swim- 
ming on the surface of the water, or even with its base 
sunk considerably below it, to furrow in a straight line tho 
summits and sides of the hills, and the bottoms of the inter- 
vening valleys. It would be carried over the inequalities of 
the country without touching the lowest depressions. In- 
stead of ascending the mountains, it would remain stranded 
against any elevation which rose greatly above its own base, 
and, if caught between two parallel ridges, would float up 
and down between them. Moreover, the action of solid, un- 
broken ice, moving over the ground in immediate contact 
with it, is so different from that of floating ice-rafts or ice- 
bergs that, though the latter have unquestionably dropped 
erratic boulders, and made furrows and striae on the surface 
where they happened to be grounded, these phenomena will 
easily be distinguished from the more connected tracks of 
glaciers, or extensive sheets of ice, resting directly upon the 
face of the country and advancing over it. 
* See " Glacial Phenomena in Maine/' Atlantic Monthly, 1866. 
