INTRODUCTION. XV 



place, does not match well when grafted on to the triple- 

 jet. The peculiar advantages of the lime wheel are lost by 

 a flat-side exposure. The several lenses of the objective, 

 when taken apart by the curious, are often replaced hap- 

 hazard, to the confusion of all distinctness in the image. 



Many operators persist in standing at the front of the 

 instrument, with back to the screen because the old lan- 

 terns obliged them to instead of standing behind, facing 

 the screen, according to directions. 



It is a mistake to suppose that the Lime-light Sciopticon 

 is not as effective as the so-called Stereopticon, because it is 

 smaller. The old style must be made large, because of the 

 material of which it is made, and the amount of heat con- 

 fined in it. The apparatus herein represented, beside 

 being more convenient, is in every respect fully equal to 

 the best, with many points of advantage for producing the 

 intensest lime-light. 



Lantern Projections as an Educational 

 Appliance. 



The pathway to learning, though proverbially not a 

 royal road, is, nevertheless, made pleasanter and less diffi- 

 cult by the pictorial illustrations now brought to bear in 

 schools of every grade, and on subjects of almost every 

 variety. 



Small pictures, though invaluable for private use, seem 

 comparatively tame when passed from hand to hand for the 

 entertainment of a company, but when projected to life- 

 size, they seem like living reality, and address themselves 

 to multitudes at once. They are viewed with cumulative 

 enthusiasm when all eyes are concentrated upon the views 

 under discussion one by one, other objects being kept dark, 

 and so out of mind. 



