DEDICATION* vii 
Of late Years, indeed, the Expence 
has been much lefs ; but then new 
Difcouragements have flatted up 
from Miftake and Prejudice. 
For Many have been frighted from 
the Ufe of it, by imagining it re¬ 
quired great Skill in Optics, and 
Abundance or other Learning, to 
comprehend it to any Purpofe : 
whereas nothing is really needful 
but good GlaiTes, good Eyes, a little 
Practice, and a common Underftand- 
ing, to diftinguifh what is feen ; and 
a Love of Truth, to give a faithful 
Account thereof. Others have con- 
fidered it as a mere Play-thing, a 
Matter of Amufement and Fancy, 
only, that raifes our Wonder for a 
Moment, but is of no farther Ser¬ 
vice : which Miftake they have fall¬ 
en into, from being unacquainted 
A 4 with 
