XVI INTKODUCTION. 



Without the expense or fatigue of travel, as has been 

 truthfully and glowingly said, the beholders are carried, in 

 imagination, to far distant lands, where they may gaze 

 upon the art treasures and wonders of the old world, or on 

 the mystic temples and pyramids of the river Nile. They 

 may run riot through the beautiful palaces of Versailles, 

 or may see pass before them a panorama of events covering 

 ages of ancient history. 



These wonderful sun-pictures, seen as they are, magnified 

 and illuminated by the intense lights used, convey to the 

 mind of the spectator a better idea of the places and scenes 

 depicted than could be had by reading volumes upon 

 Volumes of books of travel. In speaking of the statuary 

 shown, the artists themselves say, that the fullest beauty of 

 the original sculpture is stereoscopically reproduced ; in fact, 

 the marble seems standing out before you in bold relief. 



Projected pictures in the lecture room have pe- 

 culiar advantages over charts and sketches, which are 

 so much and so deservedly praised by modern educators. 

 They arrest attention, as when there came forth fingers of a 

 man's hand and wrote upon the plaster of the wall in 

 Belshazzar's palace. They are not subject to wear and 

 tear, like unwieldy picture charts let down from rollers or 

 sorted out of mammoth portfolios, but they follow one 

 another without fuss or confusion, " like the baseless fabric 

 of a vision," and then dissolve away and relieve us from 

 all care. They may be enlarged or contracted, or raised or 

 lowered, or faced to right or left, or changed from grave to 

 gay, or varied by a succession of surprises with the greatest 

 facility, though in appearance they are as large and solid 

 as the Alps. 



They are free from the confusing gloss of painted and 

 Varnished surfaces ; they are seen from every direction in the 

 best light, and are themselves the source of sufficient light 



