n5 



Observations for latitude were made with a 6 inch sextant and co- 

 vered mercury trough. 



Heights were meaaured by boiling - point instrument with thermo- 

 meters verified at Kew, and two aneroids. 



OBSERVATIONS OF LATITUDE MADE BY THE AUTHOR. 



The town of Fuerte, 25° 30' 30" North. 



Agua Caliente de Baca 26 



Rancho of Septentrión, 26 



Santiago near Bahuina, 27 



Town of Cuiteco, 27 



Ojito de Barranca at the bend of 



the Urique river, 27 



Bocoyna on the Rio Conchos, 27 



Note added in the Press. 



The Author's attention has been directed to the Bosquejo geológi- 

 co de México, 1897, numbers 4, 5, and 6, whicli contain a general account 

 of the geology of México, and some preliminary notes on the provinces 

 of Chihuahua, Sonora, and Sinaloa. 



(Eeprinted from the ProceeJings of the Eoyal Dublin Society, August 1899). 



bibliografía. 



Bibliothéque Technologique. Les Phénomenes électriques 

 et leurs applications. Étude historique, technique et économi- 

 que des transformations del'éuergie électrique parHenry Vi- 

 yarez, anclen eleve de l'École Polytechnique, Expert prés les 

 Tribunaux.— París, G. Carré et C. Naud. 1901. 8? 574 pages. 

 254 figs. 15 fr. relió. 



Non parece que esta obra está llamada á satisfacer á los deseos de mu- 

 chas personas, ingenieros, jefes de industrias, etc., que necesitan conocer 

 loB principios generales de la Electricidad como los de la Física y la Meca- 



