PREFACE TO THE SECOND 

 EDITION. 



It cannot but be highly gratifying to the author 

 of any work to find that his efforts have been 

 appreciated, and more especially when that appre- 

 ciation leads to the issue of further editions. 



I have therefore much pleasure in saying that, 

 owing to the demand for the first edition having 

 exhausted the issue, and from the flattering notices 

 appearing in nearly all sections of the press, it has 

 become necessary to issue this second edition. 



As already stated in the preface to the first edition, 

 the book does not profess to have any special value 

 to the learned in the science, but to be suited to the 

 requirements of beginners. This is all I claim, 

 and if I have succeeded in my intentions, am amply 

 satisfied. While saying so much, attention may be 

 drawn to the fact that the present edition is greatly 

 enlarged, and I venture to hope improved. Altera- 

 tions in the text and additions such as were deemed 

 advisable have been made, and although the first 

 book was to some extent applicable mainly to 



