THE MOST SERENE, 

 THE MOST POWERFUL KING AND LORD, 



FREDERICK, 



KING OF PRUSSIA, MARGRAVE OF BRANDENBURG, HIGH 



CHANCELLOR AND ELECTOR OF THE HOLY ROMAN 



EMPIRE, SOVEREIGN AND ARCH-DUKE OF 



SILESIA, ETC. 



MY MOST GRACIOUS KING AND LORD, MOST SERENE, 



MOST MIGHTY KING, MOST GRACIOUS KING AND LORD ! 



The feeling of personal unworthiness and the splendour of 

 the throne cannot make me so timid and fainthearted, but that the 

 favour which the most gracious of Monarchs extends with equal magna- 

 nimity to all his subjects, inspires in me the hope that the boldness which 

 I take upon me will not be regarded with ungracious eyes. With the most 

 submissive respect I lay herewith at the feet of your Royal Majesty a very 

 sb'ght proof of that zeal with which the Academies of Your Highness are 

 stimulated by the encouragement and protection of their enlightened 

 Sovereign to emulate other nations in the sciences. How happy would 

 I be, if the present Essay should succeed in obtaining the supreme 

 approbation of our Monarch for the efforts with which the humblest 

 and most respectful of his subjects has unceasingly striven to make himself 

 in some measure serviceable to the good of his country. With the deepest 

 devotion till death, 



I am, 



YOUR ROYAL MAJESTY'S 



Most humble Servant, 



THE AUTHOR. 



K.ONIGSBERG, 

 i^tA March, 1755. 



