Vol. 51.] ME. J. E. MARR ON THE TARNS OE LAKELAND. 47 



I have proved that it does, and in all the others which I have 

 examined, either that it probably or possibly does. 



I have not touched on the origin of the larger lakes, feeling that 

 it would be safer to suspend for the present our judgment concerning 

 their mode of origin. The researches of other writers have shown 

 that they may be rock-basins ; whether it has yet been proved that 

 they are is a matter of individual opinion. 



In conclusion I have to state that the late Mr. Topley very kindly 

 furnished me with some unpublished soundings of some of the tarns, 

 which are preserved amongst the records of H.M. Geological Survey 

 at the office in Jermyn Street. 



EXPLANATION OF FIGURES. 



Fig. 1 (p. 36). Ideal section across a moraine-blocked valley, where the lowest 

 part of the moraine (x) does not coincide with the originally lowest 

 part of the valley. The diagonally shaded portion represents solid 

 rock, that with the circles, moraine. The waters would be ponded 

 back in the valley above the moraine, at first to the level of the top of 

 the moraine at x, afterwards and more permanently, when the stream 

 issuing from the tarn cut through the moraine, to the level of the 

 broken line, corresponding with the level of the solid rock below the 

 point x. [In the figure, the broken line is drawn a little too high.] 



(If the original valley sloped uniformly on this side to its former 

 base, the stream would no doubt cut along the junction between 

 moraine and rock, but if a ledge of rock such as that represented in 

 the figure projected upward, the stream would continue at the higher 

 level.) 



Fig. 2 (p. 37). Plan of Smallwater (scale : 4^ inches =1 mile). In this and the 

 following plans, the streams at present entering into or issuing from 

 the tarns are represented in continuous lines, the former courses of 

 the moraine-blocked streams by broken lines. 



Fig. 3 (p. 37). Section across Smallwater Beck (S.B.), where it issues from the 

 tarn. Diagonal lines represent solid rock, and circles moraine. To 

 the left of the beck is seen the former valley, now moraine-blocked. 



Fig. 4 (p. 38). Section across Smallwater Beck (S.B.) about 50 yards below 

 its exit from the tarn. R, ridge of rock separating the beck from the 

 old moraine-blocked valley, V. Diagonal lines and circles have the 

 same significance as before. 



Fig. 5 (p. 39). Plan of Codale Tarn. Scale : 4£ inches=l mile. 



Fig. 6 (p. 40). Plan of Lever's Water (Le) and Low Water (L). Scale : 1 inch 

 = 1 mile. 



Fig. 7 (p. 41). Plan of Lever's Water. Scale : 6 inches=l mile. The course of 

 the old valley is here represented by the contour-lines drawn (25 feet 

 apart) between 1200 and 1600 feet in the neighbourhood of Simon's 

 Nick (S), and the exit of Lever's Water Beck (L.B.) from the tarn. 

 Its course is at first due south, as shown in the preceding figure. 



Fig. 8 (p. 43). Plan of Burnmoor Tarn. Scale : 1 inch=l mile. Showing the 

 exit from near the N. end of the tarn into Whillan Beck ( W) and the 

 position of the cirque-like cliff (O) at the head of Miterdale (M) at 

 the point where the 800-foot contour-line crosses that valley. 



Fig. 9 (p. 44). Plan of Sprinkling Tarn. Scale 6 inches=l mile. Showing the 

 present and former exits, and the rocky promontory (P) nearly cutting 

 the tarn into two. 



Fig. 10 (p. 45). Plan of Harrop Tarn. Scale : 4£ inches =1 mile. The broken 

 line represents the moraine-blocked valley, whilst the dotted lines 

 show the contour-lines between 600 and 1000 feet. 



Fig. 11 (p. 46). Section across Dob Gill and the old valley to the north-west 

 of it, drawn about \ mile below the tarn. 



