X PREFACE. 



sary technicalities, and to introduce correct teaching into 



popular works, so as to make them the fit commence- 

 ment of the pursuit of real science. The many excel- 

 lent publications bearing his monogram are the best evi- 

 dence of the success that he attained. 



In the humble hope that my feeble efforts may not 

 disgrace that impress, nor be found altogether un- 

 worthy of the cause in which they have been exerted, 

 I commend the result of my labours to the tender 



treatment of the indulgent reader. 



S. O. G. 



Dalston Rise, '31st August, 1867. 



