Page:Scott's Last Expedition, Volume 1.djvu/613

1911] but we saw the instrument detached when the slow match burned out. I'm afraid there is no doubt it fell on the glacier and there is little hope of recovering it. We have now decided to use a thread again, but to send the bobbin up with the balloon, so that it unwinds from that end and there will be no friction where it touches the snow or rock.

This investigation of upper air conditions is proving a very difficult matter, but we are not beaten yet.

Wednesday, August 30.—Fine bright day. The thread of the balloon sent up to-day broke very short off through some fault in the cage holding the bobbin. By good luck the instrument was found in the North Bay, and held a record.

This is the fifth record showing a constant inversion of temperature for a few hundred feet and then a gradual fall, so that the temperature of the surface is not readied again for 2000 or 3000 fect. The establishment of this fact repays much of the trouble caused by the ascents.

Thursday, August 31.—Went round about the Domain and Ramp with Wilson. We are now pretty well decided as to certain matters that puzzled us at first. The Ramp is undoubtedly a moraine supported on the decaying end of the glacier. A great deal of the underlying ice is exposed, but we had doubts as to whether this ice was not the result of winter drifting and summer thawing. We have a little difference of opinion as to whether this morainic material has been brought down in surface layers or pushed up from the bottom ice layers, as in Alpine glaciers. There is no doubt that the glacier is