97 



the dip of the needle 42*1°. The needle oscil- 

 lated 229 times in 10'. Perhaps masses of 

 brown iron ore, included in the calcareous rock> 

 caused a slight augmentation in the intensity of 

 the magnetic forces. I do not give here the ex- 

 periments made with an invariable pendulum ; 

 since, notwithstanding the care I took in these 

 experiments, I think them defective, on account 

 of the imperfect suspension of the rod of the 

 pendulum. 



On the 14th of September we descended the 

 Cocollar, toward the Mission of San Antonio. 

 The road led at first across savannahs strewed 

 with large blocks of calcareous stone, and we 

 then entered a thick forest. After having pass- 

 ed two ridges of mountains extremely steep *, 

 we discovered a fine valley five or six leagues in 

 length, pretty constantly following the direction 

 of east and west. In this valley the Missions of 

 San Antonio and Guanaguana are situate ; 

 the first is famous on account of a small church 

 with two towers, built of brick, in a pretty good 

 style, and ornamented with columns of the Do- 

 ric order, the wonder of the country. The pre- 



* These ridges, rather difficult to climb toward the end of 

 the rainy season, are known under the singular names of 

 Los Tepes and Fantasma. The limestone, whenever it ap- 

 pears uncovered in these places, is directed, hor. 4 — 5. (Dip 

 of the strata, 40° S. E.) 



VOL, III. H 



