88 SEFSTROM ON THE FURROWS WHICH TRAVERSE 
be in itself, it still requires a long practice in order to make one — 
competent to undertake it. 
§ 2. 
Some observations on the determination of the direction of 
the furrows. 
When I commenced my observations on the furrows, it oc- 
curred several times, when I again visited the same district and 
had not borne in mind the places which I had before observed, 
that different results were obtained; not varying very much, 
but more so than would have been caused by the indistinctness 
of the furrows. Upon a closer investigation, the error was found 
in the greater number of cases to be caused by inattention to 
the situation of the place observed, as well as whether the fur- 
rows were normal or not; in other words, whether the furrows 
observed went over the top of the hill on which the observations 
were made, or if they in their continuation went over the east- 
ern or western side. As far as the observations were continued 
around Fahlun, it was necessary to observe whether they were 
made on the top of the hill or on the northern end; but as in 
other places it has been found that the furrows do not always 
go so nearly from north to south, it was therefore necessary to 
try another method in order to perfect the observations. For 
this reason I gave up fixing my attention to the compass direc- 
tion ; but in its stead at first, as near as possible, from a view 
of the surrounding country, by examining the maps, and from 
information collected from persons well acquainted with the lo- 
cality, I procured a good idea of the form of the hills in ques- 
tion ; after which I had no other resource than to observe the 
furrows on every place possible, as well as to note them down; 
then with the compass placed on the map and laid parallel with 
the north and south line, I easily found which furrows at the 
foot of the mountain passed over the top. The side of the 
mountain where the furrows are found I call the opposing side 
(stétsidan), on the hypothesis that the flood of boulders had 
rushed against it; and the opposite side of the mountain I call 
the /ee-side (lasidan). After having gained experience, and par- 
ticularly when, making my observations, I did not find myself 
surrounded by high wood, it soon appeared which side of a 
lesser slope (of not more than one Swedish mile in extent) 
was the opposing side. Assuming that we are always viewing 
the hill from this side, the opposite side will always be the lee- 
side, and the other two the right and the /eft; the former, in 
