Correspondence — //. T. Ferrar. 189 



5 cm. iu diameter, resting on three screws, one of wliich has 

 a graduated liead, is movable vertically along, and rotatable about its 

 axis, and by rotation of the graduated screw the axis of the cylinder 

 is inclined at a kuowii angle to the grinding lap. A crystal suitably 

 mounted is brought by means of these two rotations into any desired 

 position, a series of chucks of different inclinations being provided for 

 holding it. The zero position is determined optically. A graphical 

 method of determining the requisite rotations was described. 



co:E?,K,E!si=oisri3E:isrcE. 



THE NATURE AND ORIGIN OF FIORDS. 



Sir, — Although Professor J. W. Gregory denies the presence of 

 fiords in South Victoria Land in his recently published work with 

 the above title, I feel bound to point out that fiord-valleys whose 

 characteristics agree in all essentials with his fiord - valleys 

 (pp. 17 and 19) occur, if somewhat infrequently. 



The existence of fiord-valleys on this coast strengthens rather than 

 weakens his main theme, and, as we are led to expect (p. 479), 

 a simple foundering, such as that which has taken place in South 

 Victoria Land, would not form a full fiord-system. In singling out 

 only two of the many ' inlets ' which indent the coast he implies 

 (p. 370) that they are not even simple fiords. The first, Tucker Inlet, 

 has had only its entrance fixed by ships passing along the coast, and 

 therefore it is not likely that any branches or arms, if such exist, 

 would be indicated on the published maps ; the second, Granite 

 Harbour, lately surveyed in detail by Mr. Uebenham of Scott's 

 ill-fated expedition, in many respects would resemble a fiord were 

 the sea to encroach 1,000 feet or so upon the land. Likewise the 

 Ferrar Glacier and its branches, if depressed some 3,000 feet, would 

 provide all the essential characteristics of a fiord (pp. 66 and 385), and 

 the accompanying sketch-map is intended to depict the coastlines 

 subsequent to such a submergence of the valley (see p. 190). 



The points outlined above should have an important bearing on the 

 subject of glacial erosion, i.e. the erosive power of water-substance in 

 its solid form (ice), which once again is under discussion. Professor 

 T. W. E. David and Mr. Priestley, after boldly showing on a map 

 (Eleventh International Geological Congress) a network of faults 

 determining the main tectonic features of South Victoria Land, have 

 joined the ranks of the ' Erosionists '. (I noticed that only one of the 

 series of east and west series of faults was made to coincide with an 

 important east and west valley.) So too has Mr. Griffith Taylor iu 

 his contribution to the narrative of " Scott's Last Expedition" ; but 

 he does not explain why the glaciers which gouged out the valleys 

 leading into Granite Harbour did not remove Mount Suess, nor wliy 

 the ice-stream which excavated Taylor Valley (the North Fork of 

 the Discovery and Nimrod maps) did not remove the two projecting 

 Riegeln. 



During my traverse of the then unexplored Ferrar Glacier, I, like 

 Professor Gregory (Preface), "found it difficult to determine which 



