PREFACE. 



larged by Mr. H.V'JKSBEE, Dr. DESAGCLIERS, Mr 

 WHISTOX, Mr. COTES, Mr. WIIITESIDE, Dr. BRAD- 

 LEY, our late Regius and Savilian professor of 

 Astronomy, and the Reverend Dr. BLISS his suc- 

 cessor. Nor has the same been neglected by 



Dr. JAMES, and Dr. DAVID GREGORY, Sir ROBERT 



STEWART, and after him Mr. MACLAURIN. Dr 



HELSHAM in Ireland, Messrs S'GRAVESANDE and 

 MUSCHENBROEK, and the Abbe NOLLET in France, 

 have also acquired just applause thereby. 



The substance of ray own attempt in this way of 

 instrumental instruction, the following sheets (ex- 

 clusive of the astronomical part) will shew : the 

 satisfaction they have generally given, read as lec- 

 tures to different audiences, affords me some hope 

 that they may be favourably received in the same 

 form by the public. 



I ought to observe, that though the five last Lec- 

 tures cannot be properly said to concern experi- 

 mental philosophy, I considered, however, that 

 they were not of so different a class, but that they 

 might, without much impropriety, be subjoined to 

 the preceding ones. 



My apparatus (part of which is described here, 

 and the rest in a former work*) is rather simple 



* Astronomy explained upon SIR ISAAC NEWTON'S principles, 

 \r. ! made easy to those who have not studied mathematics. 



