54 SPECIAL RESULTS IN THE URANOLOGICAL 



.looking up from the bottom of deep shafts to the zenith, 

 but without ever seeing a star ; nor have I since found an 

 individual in Mexican, Peruvian, or Siberian mines, who 

 had ever heard of stars being seen in the day-time, although 

 in such different latitudes as those embraced by my inquiries 

 and experience in both hemispheres, a sufficient number of 

 zenith stars must have presented themselves advantageously. 

 This entirely negative evidence renders very remarkable the 

 highly credible testimony of a celebrated optician who, in 

 early youth, saw the stars during bright day -light through a 

 chimney. ( no ) Phenomena whose visibility depends on an 

 accidental concurrence of favourable circumstances must 

 not be denied because they are of rare occurrence. 



This principle also applies, I think, to the statement of 

 the always careful and accurate Saussure, in reference to 

 stars being seen with the naked eye on the ascent of Mont 

 Blanc, at a height of 11970 (12757 Eng.) feet. He says, 

 t( Quelques-uris des guides m'ont assure avoir vu des etoiles 

 en plein jour ; pour moi je n'y songeois pas, en sorte que 

 je n'ai point ete le temoin de ce phenomeiie ; mais I' asser- 

 tion uniforme des guides ne me laisse aucun doute sur 

 la realite. ( 1H ) II faut d'ailleurs etre entierement a Fombre, 

 et avoir meme au-dessus de la tete une masse d'ombre d'une 

 epaisseur considerable, sans quoi Fair trop fortement eclaire 

 fait evanouir la foible clarte des etoiles." The conditions 

 are, therefore, almost entirely the same as those presented by 

 the reservoirs of the ancients and the chimney before referred 

 to. I have not found this remarkable statement (bearing 

 date the morning of the 2nd of August, 1787) repeated in 

 any subsequent journey in the Swiss mountains. Two highly 

 informed and excellent observers, the brothers Hermann 

 and Adolph Schlagintweit, who have recently explored the 



