NOTES. CXI 



gitnde of Jorullo as I do, 2 25' W. of Mexico (101 29' W. of Greenwich), dif- 

 fers from me in the latitude. Is his latitude for Jorullo (18 53' 30"), which 

 comes very near to that of Popocatepetl (18 59' 47"), founded on later obser- 

 vations with which I am unacquainted ? In my Recueil d'Observations Astrono- 

 miques, vol. ii. p. 521, I have said expressly, "Latitude supposee, 19 8', de- 

 rived from good star observations at Valladolid, which gave 19 52' 8", and 

 from the Itinerary direction." I only subsequently recognised the importance of 

 the latitude of Jorullo when I was laying down the large Map of Mexico, and 

 entering upon it the volcanic chain which runs east and west. 



As in these considerations on the origin of Jorullo I have repeatedly alluded 

 to traditionary stories still prevalent in the country, I will refer at the end of 

 this long note to what is still a very popular tale, which was alluded to 

 by me in another work (Essai Pol. sur la Nouv. Espagne, t. ii. 1827, p. 172): 

 "Selon la credulite des indigenes, ces changemens extraordinaires que nous 



venons de de'crire sont 1'ouvrage des moines Aux Playas de Jorullo, 



dans la chaumiere que nous habitions, notre hote indien nous raconta qu'en 1759 

 des Capucins en mission precherent k 1'habitation de San Pedro, mais que, 

 n'ayant pas trouve un accueil favorable, ils chargerent cette plaine, alors si belle 

 et si fertile, des imprecations les plus horribles et les plus complique'es ; ils pro- 

 phe'tiserent que d'abord 1'habitation seroit engloutie par des flammes qui sorti- 

 roient de la terre, et que plus tard 1'air ambiant se refroidiroit a tel point que 

 les montagnes voisines resteroient eternellement couvertes de neige et de glace. 

 La premiere de ces male'dictions ayant eu des suites si funestes, le has peuple 

 indien voit dejk dans le refroidissement progressif du volcan le pre'sage d'un 

 hiver perpetuel." 



The first printed account of the catastrophe (next to the poetical one of Lan- 

 divar) was no doubt that already referred to in the Gazeta de Mexico, de 5 de 

 Mayo 1789 (t. iii. Num. 30, p. 293297). It had the modest heading : 

 "Superficial y nada facultativa Descripcion del estado en que se hallaba el 

 Volcan de Jorullo, la manana del dia 10 de Marzo de 1789 ;" and was occa- 

 sioned by the expedition of Riano, Franz Fischer, and Espelde. Later, in 1791, 

 the botanist Mocifio and Don Martin Sesse, from the Nautico-Astronomical Ex- 

 pedition of Malaspina, visited Jorullo from the Pacific coast. 



( 431 ) p. 295. My barometric measurements give: for Mexico, 7469 feet ; 

 Valladolid, 6407 feet ; Patzcuaro, 7225 feet ; Ario, 6353 feet ; Aguasarco, 

 4988 feet ; and for the old plain of the Playas de Jorullo, 2583 feet. (Humb. 

 Observ. Astron. vol. i. p. 327 ; Nivellement barome'trique, No. 367 370.) 



C 432 ) p. 295. I find, taking the old level of the Playas at 404 toises (2583 

 feet): for the convexity of the Malpais, 3114 feet ; for the crest of the great 



