274 Mr. Rose's Sketch of the Geology of West Norfolk. 



satisfactory. For the purpose, however, of dispelling any 

 doubts of its accuracy which may exist in the minds of others, 

 I undertook another series of test experiments, to the descrip- 

 tion of which I shall now proceed. 



[To be continued.] 



XXXIII. A Sketch of the Geology of West Norfolk. By 

 C. B. Rose, Fellow of the Royal Medical and Chirurgical 

 Society of London. 



[Continued from p. \ 82.] 



The Chalk Range. 



THE chalk hills of West Norfolk constitute a portion of 

 the great range of that formation extending across En- 

 gland in a south-westerly direction from Flamborough Head 

 in Yorkshire to near Sidmouth in Devonshire. The greatest 

 elevation they attain in this county is insignificant in com- 

 parison with the hills at either extremity of the range: at 

 Sedgeford, and between Heacham and Hunstanton, the face 

 of the country possesses some boldness of feature, and again 

 near Holt the hill and vale are strongly contrasted : with 

 these exceptions, the course of the chalk outcrop through the 

 county is marked by the gently undulating surface peculiar 

 to such districts. 



I have been favoured with a communication from Captain 

 Robe, R.E., in reply to my inquiry respecting the height of 

 the hills in this portion of the county. After stating that the 

 " triangulation of Norfolk was performed with instruments 

 too small to be depended upon for the vertical angle obser- 

 vations," he continues, " I cannot now lay my hands on the 

 sketch on which my judged altitudes were written ; but if I re- 

 collect right, I considered the ground round Docking to be the 

 highest, which was somewhere about 600 or 650 feet ; Swaff- 

 ham is probably 4-50 or 500, Great Massingham 600. But 

 these are very rude guesses ; indeed without using accurate in- 

 struments, it would be impossible to class the several ranges 

 according to their relative altitudes, as they vary so very little 

 from each other, and few of them exceeding 600 feet." 



The width of the range taken at SwafFham is about seven 

 miles; its course through the county is nearly due north and 

 south, and its escarpment is to the west, forming generally a 

 somewhat abrupt declivity, bounded along the greater part of 

 its extent by a narrow valley occupied by the lowest strata of 

 chalk, and the gault. The strata dip to the south-east, pro- 



