" In former times there were many men eminent in all the branches 

 of human learning, but, as regards the great masses of mankind, 

 the avenues of knowledge were to a certain degree closed ; but the 

 arrangements of later periods, which are improving from day to 

 day, tend to diffuse among the great mass of the community, or, at 

 all events, among all who are willing to receive instruction, the 

 results of the labours of science and the fruits of the investigations 

 of the learned. 



" The intellectual qualities, as well as the moral feelings of our 

 nature, are scattered broadcast over the face of the earth. We find 

 them everywhere, in the lowest classes as in the highest." Lord 

 P aimer ston, at Manchester, Xovember 6th, 1856. 



ERRATA. 



Page 47, line 6 from bottom, after " Harris's figure" insert " (Exposition, 

 _ pi. 27, fig. 2)." 

 „ 51, line 19, for " jEschnia'' read " JEscJma." 

 ,, 55, line 10 from bottom, after " ( $ ) ;" insert " ( $ )•" 

 „ ,, line 2 from bottom, after " ( $ ) ; : ' insert " ( $ )." 

 „ 57, line 4 from bottom, after " Dublin" insert " University." 

 „ 63, line 10 from bottom, for " Whitsund" read " Whitsand." 

 „ 64, line 2, erase " Dej. Spec." 

 „ 70, line 14, for " Fig. 7" read " Fig. 8." 



