TO HIS ROYAL HIGHNESS 

 PRINCE AUGUSTUS FREDERICK, 



DUKE OF SUSSEX, K.G. 



PRESIDENT OF THE ROYAL SOCIETY, 

 &C. &C. &C. &C. 



THIS TREATISE 



IS, WITH PERMISSION, HUMBLY DEDICATED, 



AS A TRIBUTE OF PROFOUND RESPECT AND GRATITUDE 



FOR THE BENEFITS RESULTING TO 



SCIENCE 



AND ITS CULTIVATORS, 

 FROM HIS ILLUSTRIOUS PATRONAGE, 



BY HIS DEVOTED, HUMBLE SERVANT, 



P. M. ROGET. 



