PREFACE. 



T, 



HE Authors of Original Papers in the present Volume, 

 are Sir H. C Englefield, Bart. M.RF.R.S.; Mr. H. 

 Steinhauer; Mr. John Gough; Ra. Thicknesse, Esq.; Mr. 

 ¥m. Wilson; C.Wilkinson, Esq.; J.Whitley Boswell, 

 Esq.; Mr. W. Brande ; Aletes ; Mr. John Dalton ; Capt. 

 J. Mortlock ; W. F. S. ; Mr. Charles Sylvester ; Mr. Ezekiej 

 Walker; T. B. C. ; Jos. Huddart, Esq. F.R. S.; E. O ; 

 W. B. ; Mr. N. Mendelfhon; C. L. ; Mr. Accum ; Right 

 Hon. Sir Joseph Banks, Bart. P. R. S. &c. &c; Mr. R. 

 Matthews; Mr. J. Biddle; An Old Correspondent.— Of 

 Foreign Works, Thenard ; Hesinger; Bergelius; Morozzo; 

 Bucholz; Dartigues; Schoerbing; Boullay; Lagrange; Lus- 

 sac; Errnan. — And of English Memoirs, abridged or ex- 

 tracted; SmithsonTennant, Esq. F.R.S.; W. H. Wollaston, 

 M.D. F.R. S.j C. Hatchett,Esq. F.R.S.; Gregory Watt, 

 Esq.; Right Hon. C. Greville, V. P. R.S.; George Pearson, 

 M.D.F.R.S.; J. Hinckley, Esq.; F.S.A.; T. A. Knight, 

 Esq. 



Of the Engravings the Subjects are, 1. An ancient Egyp- 

 tian Engraving in Symbols, supposed to be astronomical. 

 2. Figures to illustrate the Galvanic Charge, by C. Wilkin- 

 son, Esq. 3. Outlines of Pendulous Measures of Time, by 

 J. W. Boswell, Esq. 4. Figure to illustrate Mr. Gough's 

 Theory of the Augmentation of Sound, by communicated 

 Vibrations. 5. Instrument for surveying, by Capt. J. Mort- 

 lock. 6. Instrument for taking Designs from Nature. 7, 

 Plan and Sections of an improved Air-Pump, by Mr. Men- 

 delsshon. 8. Figures to illustrate Mr. Gough's Theory of 



the 



