264 



The new salt works of Araya have five reser- 

 voirs, or pits, the largest of which have a regular 

 form, and two thousand three hundred square 

 toises surface. Their mean depth is eight 

 inches. Use is made both of the rain waters, 

 which, by filtration collect at the lowest part of 

 the plain, and of the water of the sea, which 

 enters by canals, or martellibres, when the flood 

 tide is favoured by the winds. The situation of 

 these salt works is less advantageous, than that 

 of the mere. The waters which fall into the 

 latter pass over steeper slopes, washing a greater 

 extent of ground. The natives make use of 

 hand pumps to convey the seawater from one 

 principal reservoir into the pits. It would ne- 

 vertheless be easy enough to employ the wind 

 as the moving power, since the breeze always 

 blows strong on these coasts. The earth already 

 washed is never carried away here, as is the cus- 

 tom from time to time in the island of Marga- 

 retta ; nor have wells been dug in the muriati- 

 ferous clay, to find strata richer in muriat of 

 soda. The saltmen generally complain of want 

 of rain ; and in the new salt works it appears to 

 me difficult to determine, what is the quantity 



spheres. The relative antiquity of the formations is the prin- 

 cipal object of a science, which is to render us acquainted 

 with the construction of the Globe ; that is to say, the nature 

 and superposition of the stony strata, which constitute the 

 exterior crust of our planet. 



