54 



ME. G. BUSK ON THE AJSTCLENT OE 



occurs. To render this clear, a few particulars respecting the geological relations of 

 the rock must be given. The substance of what I have to say on this point is taken 

 from Mr. Smith's (of Jordan Hill) excellent and, as it appeared to Dr. Falconer and 

 myself, extremely accurate observations ' on the geology of Gibraltar. 



The rock or, more properly speaking, the mountain peninsula of Gibraltar is a 

 detached promontory, about three miles long and three quarters of a mile in its 

 greatest width, running in a direction nearly due north and south, and attaining an 

 elevation of more than 1400 feet above the level of the sea. Its base on the west side 

 is washed by the waves of the Atlantic, and on the eastern by those of the Mediter- 

 ranean ; and at the northern end it is connected with the mainland by a flat sandy 

 isthmus about half a mile wide and rising not more than 10 feet above the level of the 

 water. 



The entire mass of the promontory is divided into two principal segments, of which 



Kg. 1. 



Outline sketch of the Hock of Gibraltar. 



the northern, which includes three fourths of the length, is much more elevated than 

 the southern. The elevated portion, again, is subbivided into three distinct segments or 

 eminences, separated by two irregular, though nearly equidistant, depressions, which 

 are termed the northern and southern "quebrada " or "broken ground" (a, b, fig. 1). 



The northernmost portion of the rock is terminated at the north end by a nearly 

 vertical cliff 1250 high. The middle portion, or " Middle Hill," as it is termed, rises 

 to a height of 1255 feet at the " Signal-station," whilst the southern elevation, the 

 "Pan d'Assucar," or " Sugar Loaf," rises to a height of 1408 feet, where it is crowned 

 by " O'Hara's Tower." 



From this eminence there is a rapid declivity to the south, but which is not so 

 precipitous as to prevent its easy ascent. The declivity, after falling about 1000 feet, 

 terminates in the " Windmill-Hill Flats," c, a plateau, or nearly level plain, about half a 

 mile long, and a quarter of a mile wide. At its northern limit, close to the Military 



' In his ' Researches in Newer Pliocene and Pleistocene Geology,' Glasgow, p. 98, 1862 ; or Geol. Soc. Journ. 

 1846, ii. pp. 41-51. 



