AND PORTO SANTO. 137 



artificial horizon, can never be a very nice observation, unless a 

 man be blessed with the tact of De Humboldt. The difficxdty of 

 not seeing the hairs of the telescope of the circle when a star was 

 brought within the field, and the inconvenience of affixing a lamp, 

 is remedied by making the horizontal hair sufficiently thick to 

 ecUpse the star when brought behind it. This instrument, and 

 a telescope for echpses and occultations, I am proud to say, I owe 

 to the generous interest of my friends in the University of Cam- 

 bridge. I made the Consul's house in Funchal 32° 38' 22 " N. and 

 16° 53' 34" W. by the mean of several lunar distances. Unfortu- 

 nately I could not afford a chronometer, but this inconvenience 

 may in some degree be obviated at the expense of time and labour, 

 as I hope to prove in my next publication. It is but prudent, 

 however, to wish, and endeavour to be as sparing as possible of 

 both, when travelling in the interior of Africa. "Lorsqu'un 

 gouvernement ordonne une de ces expeditions qui contribuent a 

 la connaissance exacte du globe, et a I'avancement des sciences 

 physiques, rien ne s'oppose a I'execution de ses desseins. II n'en 

 est pas de meme, lorsqu'un simple particuher entreprend a ses frais, 

 un voyage dans I'interieur d'un continent'." 



' De Humboldt, Voyage, vol. 1, 8vo. p. 63, 64. 



