TO THE READER. 



This work may be " read " by studying the drawings, with occa- 

 sional reference to the text. A description of each figure is appended 

 to it, and in most cases the page in which the subject is treated of, is 

 noted. The student will obtain more correct ideas, and in a shorter 

 time, by the attentive examination of the illustrations than by 

 reading only. 



