Glacial Lunoid Furrows. — Packard. 105 
or shoulder near the head of the pass, where steps are cut into 
the smooth, pohshed and glaciated surface. This is one of a 
series of 8])urs which extend out into the valley, from Handeck 
to the Grimsel Hotel, and judging from their highl}^ glaciated 
surface, they must have been subjected to tremendous pres- 
sure. Moreover at this point the granite showed a strong ten- 
dency to exfoliate, leaving more or less crescentic hollows. 
But on the next day when going and returning from the Aar 
glacier and passing a glacially smoothed and polished nubble of 
granite which stood directlj^ in the former path of the glacier, 
about half an hour's walk from the hotel, the probable cause of 
the numerous lunoid gouges so well developed there, occurred 
to me. It seemed c{uite plain to the minds of m3^se]f and my son, 
who accompanied me, that the transverse gouges were due to 
great pressure,causing the granite surface to exfoliate,while the 
quite regular shape of the gouges was due to the presence of 
rounded subglacial boulders of different sizes which were 
forced along between the ice and the surface of the rock. The 
gouges were on the stoss or glacial inclination of the nubble, 
the ice locally moving uphill. My former attempt at explain- 
ing the process by local back-and-forth motion of the ice, so as 
to cause the stones to turn over I was led on the spot to 
abandon. The marks both above Handeck, and in the Aar 
valley were identical with those I had many years previously 
noticed on the coast of Labrador, and near the summits of Mt. 
Baldface and Speckled mountain, and at another point near 
Goodrich's falls on the Ellis river in the White mountains. 
The gouges there, appear usually to occur on surfaces which 
presented unusual obstacles to the passage of the ice, and are 
best developed on granite rock-surfaces, which have a ten- 
dency to exfoliate, and they seem to be caused by the presence 
of one or several boulders. The curved and crescentic or 
gouge-shape of the mark appears to be due to the fact (1) 
that the glacier carried or pushed a more orless angular boulder 
over a granite nubble or spur, so that the pressure was greater 
than at other points in the valley ; (2) the more or less round- 
ed boulder, with its lower or under side perhaps somewhat flat, 
and so situated that the ice rested only on the top, occasioned 
greater local pressure than where no boulders were present; 
(3) the boulder meeting with a slight obstacle suddenly 
stopped, and the ice pushing it from behind caused it to 
