THE PEEUVIAN COASTLANDS. 287 



a great part of the year, tlie hills are covered with fog in the morning and 

 exposed to the sun in the afternoon."* 



Nevertheless a real upheaval of the land would appear to have taken place 

 after the earthquake of 1746 ; at least, the strait flowing between San Lorenzo 

 island and the mainland had become so narrow that the boys of the district were 

 able to throw stones right across from shore to shore. But the recorded changes 

 of level may possibly be due to volcanic shocks thrusting up or engulfing the 

 coastlands. San Lorenzo is still about two miles from the mainland, as before the 

 disturbance of 1746, and an old garden in which were cultivated camotes (sweet 

 potatoes) still bears its name of Camotal, but is now a marine sandbank. North 

 of the bay some sugarcane -fields have shared the same fate, while near Lurin, 

 south of Callao, the holy island of Pachacamac, two miles from the coast, was 

 still a peninsula at the time of the Conquest. The original site of Callao itself 

 lies now at the bottom of the sea, and the old sailors used to relate that when 

 passing at midnight over the submerged city they could see from their boats the 

 people seated at the doors of the houses, and even hear the shrill crow of the 

 cock beneath the waters. 



Darwin and Tschudi also speak of upheavals in the interior of the country 

 shown by the change of level in the old valleys, where the streams no longer flow 

 in the same direction as formerly. Thus the bed of the Rio Chilien, north-east 

 and north of the plains of Lima, is interrupted at one point by a hill which has 

 obliged it to open a new passage by a great bend round to the west. Another old 

 watercourse met farther north, on the road between Casma and Iluaraz, has also 

 changed its direction, leaving in one place a dry bed which was formerly tapped 

 by irrigation rills. 



The various rocks, argillaceous or sandy heights, also appear to have been 

 subject to the action of marine or fluvial waters, as shown by the erosions, the 

 siltings, and the shell-heaps strewn round about their base. In the desert regions 

 marine sandhills occupy vast spaces along the seaboard, where all are disposed 

 in medanos, or crescents, following with regularity, and by the character of both 

 slopes and of the crests everywhere indicating the direction of the prevailing 

 wind. Near Casma, in north Peru, musical notes like those of an organ are often 

 heard during the great heats of the day, emitted by a mountain covered with 

 sands. Unable otherwise to explain the phenomenon, the natives suppose that 

 the eminence is a " water volcano," and that the sound results from the liquid 

 mass boiling inside. But this music, like that of Serbal in the Sinai group, and 

 of so man}^ mountains elsewhere, must be due to the incessant movement of the 

 sand particles vibrating in the heat. The stronger the breeze the louder the 

 notes. 



Although in general somewhat regular in its trend, this part of the coast 

 presents a few small prominences, which resemble each other in their outline, and 

 which are due to the underground forces all acting in the same direction. Thus 

 the shore stretching south of the Amotape hills is diversified by a series of hooks 



* Notes of a Xaturalist in South America, p. 114. 



