May 30, 1878] 



NATURE 



119 



well known to our readers, and some further idea of it 

 may be obtained from the specimen shown in our 

 illustration (Fig. i). Things were bad enough for the 

 shore-parties, but, to judge from the description, it 

 would be as easy to go from the Crystal to the 

 Alexandra Palace over the tops of the houses dragging 

 a heavily-laden sledge after you, as to accomplish what 

 Markham and his party did. The valuable result of 

 this expedition is an extension of our knowledge of the 

 nature and formation of the ice which covers these polar 

 regions. That the inconceivably rugged and hilly nature 

 of the ice is partly due to the movement of the pack, and 

 the consequent piling of floe on floe at all sorts of 

 angles, there can be no doubt ; but the observations 

 of Dr. Moss (see our Royal Society Report this week) 

 and Lieut. Parr seem to show that the immense thick- 

 ness of the floes, exceeding eighty feet sometimes, is not 

 due entirely to the piling of floe on floe. Rather it would 



seem that the same causes are in operation here as in 

 the Alpine glaciers, and that on a thick substratum of 

 sea-ice, snow-fall after snow-fall has been accumulating 

 season after season, — for how long the daring geologist 

 alone can hazard a guess — becoming gradually condensed 

 into ice by pressure. What may be the limit of this 

 process we have no data on which to build conclusions. 

 "The N^vd-like stratification, the embedded atmospheric 

 dust, and the chemical characters of our polar floes, 

 indicate, in my (Dr. Moss's) opinion, that they are the 

 accumulated snow-fall of ages, rendered brackish by in- 

 filtration and efflorescence." The great " domed " floes, 

 he thinks, tell of gradual decay, "because, wherever we 

 got a section of them, the horizontal strata were cut by 

 the outline of the domes, and the ice of the top of the 

 dome was invariably salt. Occasionally deposits of 

 atmospheric dust were to be met with throughout the 

 stratified ice." 



Fig. I. — Newly.formed Flce-bergs. 



As to the movements of the ice in the Polar Ocean, 

 the expedition was unable to make any observations of 

 consequence, though it has made some contributions to a 

 knowledge of those of the ice in the channels through which 

 the ships passed. The general conclusion seems to be 

 that beyond the Alerfs winter quarters, though there 

 may be occasional open spaces, or polynias, the ice never 

 breaks up sufficiently to enable a ship to pass further 

 northwards, notwithstanding the observations made by 

 the Polaiis expedition. But this question of the move- 

 ments of the polar ice is just one of those that can only 

 be satisfactorily settled by a long series of observations, 

 such as those that could be made from the ring of stations 

 proposed to be established by Lieut. Weyprecht. 



The tidal observations made, especially on board the 

 Discovery, were of great value, in the opinion of Dr. 

 Haughton, who gives an abstract of the results in the 

 Appendix, and seem to confirm the observations made 



in the Polaris expedition :— " The expedition, proceeding 

 up Smith Sound, met the tide coming from the north, at 

 or near Cape Frazer, lat. 79° 40', and left behind the tides 

 of Baffin's Bay. The new tidal wave, observed on board 

 both ships, is specifically distinct from the Baffin's Bay 

 tide, and from the tide that enters the Arctic Ocean 

 through Behring's Straits ; and it is, without question, a 

 tide that has passed from the Atlantic Ocean, round 

 Greenland, northwards, and then westwards." 



As might be expected in these high northern regions, 

 there were few auroral displays, and though one, at least, 

 was remarkable, none were brilliant, and all comparatively 

 colourless. We do not read, however, that any attempt 

 was made to study this or any other light phenomenon by 

 means of the spectroscope, though, we believe, several of 

 the officers were specially instructed in the use of the in- 

 strument before the expedition set out. In this connec- 

 tion we may notice a most interesting solar phenomenon 



