288 TRAVELS AMONGST THE ORE AT ANDES, chap. xv. 



keeping guard over stores, and enjoyed a quiet month alone, 

 improving much in appearance and condition. 



My stomach had gone all wrong, ^ as people say, and repose was 

 necessary for restoration to health. During the next five weeks 

 I went little out of doors, except for promenades in the city, and 

 before we left it I had explored every street, lane, or alley in the 

 place. Jean-Antoine and I turned out each evening to do a fresh 

 section, walking warily in the centre of the thoroughfares, one a 

 little in advance of the other. By ten o'clock nearly every one 

 had gone to bed, and scarcely a sound would be heard except the 

 voices of policemen bawling at the junctions of the streets, to 

 announce their whereabouts. 



In the middle of the month, when somewhat revived, I made 

 an excursion to the Pyramids which should mark the ends of the 

 long base-line that was measured in 1736 by La Condamine and 

 his associates. In consequence of discussions which had arisen as 

 to the figure of the Earth, the French Academy of Sciences, at the 

 beginning of the last century, determined to send out two expedi- 

 tions to measure arcs at a great distance apart. One of these went 

 to the Gulf of Bothnia, and the other, composed of MM. Godin, 

 Bouguer, and La Condamine, to Equatorial America. They com- 

 menced their work on a plain to the north-east of Quito, by 

 measuring a very long base-line, and from its two ends carried a 

 chain of triangles'" (to the north beyond Ibarra, and to the south 

 to Ouenca) over more than three degrees of latitude. Towards 

 the end of their work they measured a base of verification near 

 Cuenca, and found its length by direct measurement differed from 

 the calculated length by less than two feet ! 



The toise that the French Academicians took out as an unit of 



felspar, with a ferruginous mica, grains of hematite or magnetite. . . The rock is 

 an andesite, but perhaps it is safest only to prefix the epithet micaceous."— Prof. 

 T. G. Bonney, Proc. Royal Soc, Nov. 27, 1884. 



1 This was started by exposure on March 31, 



2 A plan of these triangles is given iu PI. II. of La Condamine's work, Mesure 

 des trois premiers degres du Meridien, 4to, Paris, 1751, and also by Juan and Ulloa. 



