PREFACE. 



THE Authors of Original Papers and Communications in the 

 present Volume are Mrs. Agnes Ibbetson ; W. H. B. ; Mr. 

 John Davy; Mr. Grover Kemp; Thomas Forster, Esq.; Luke 

 Howard, Esq. ; Dr. Delaroche ; W. Moore, Esq. ; H. T. B. ; Adam 

 Anderson, Esq.; Marshall Hall, Esq.; Mathenuiticiis; Mr. Charles 

 Sylvester; Thonjas Stewart Traill, M. D. ; Mr. John Murray; 

 Richard Lovell Edgeworth, Esq. F. R. S. M. R. I. A. &c.; John 

 Farey, senr. Esq. ; Nauticus ; and Mr. John Gough. 



Of Foreign Works, M. Berthollet; M. Gay-Lussac ; M.Thenard ; 

 M. Vauqnelin; M. Mains; M. Biot; Mr. J. Cloud; M. d'Arcet ; 

 M. Decandolle; M. Vitalis; M. Haiiy; Prof. Pictet; Prof. P. 

 Prevost; Count deFourcroy ; M. Berzelius; M.Guyton-Morveau ; 

 M Kiaproth; M. A. Laugier; M. Chevreul; M.Bucholz; and M. 

 Martres. 



And of British Memoirs abridged or extracted, George Pearson, 

 M. D. F. R. S. ; Luke Howard, Esq.; the Rev. John Simpson; the 

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

 Bryan Donkin ; Mr. J. D.Ross; Mr. George Marshall; James 

 Smithson, Esq. F. R. S. ; Mr. Richard Cathery ; Everard Home, 

 Esq. F. R. S.; Thomas Andrew Knight, Esq. F. R. S. &c. ; Mr. 

 J. Hassel; Mr. Wilhani Corston; Dr. William Roxburgh; David 

 Brewster, LL. D. F. R. S. Ed.; B. C. Brodie, Esq. F. R. S."; Mr. 

 William Lester; Mr. William Salisbury ; and Mr. Samuel Roberts, 



The Engravings consist of 1 and 2. Various Figures representing 

 the Hairs and minute Cryptogamiae on Plants, greatly magnified 

 and delineated from Nature, by Mrs. A. Ibbetsop. 3. Mr. Donkin's 

 Tachometer, for ascertaining the Velocity of Machinery. 4. A 

 Hippograph, or Mode of conveying Intelligence by Cavalry. 5. 

 Mr. Ross's Machine for separating Iron Filings from those of other 

 Metals. 6. Mr. Marshall's Sash-frame for preventing Accidents. 

 7. Peduncles of Leaves delineated and dissected, to show their 

 Mechanism, by Mrs. Agnes Ibbetson. 8. Apparatus to explain 

 the Decomposition of Water in separate Vessels by Galvanism, 

 by Adam Anderson, Esq. 9. Crystals of carbonated Lime, by 

 Abbe Haiiy. 10. Plans and Sections of a Spire of a new Con- 

 struction, lately erected at Edgeworthstown, by R. L. Edgeworth, 

 Esq. F. R. S. M.R.I. A., &c. 11. Diagrams for the Demonstra- 

 tion of the Fundamental Property of the Lever, by D. R. Brewster, 

 LL. D. F. R. S. Ed. 12. Mr. Lester's Machine for washing Roots: 

 13. Mr. Salisbury's Method of packing and preserving Plants and 

 Trees. 14. The Sheffield Apparatus for cleaning Chimneys with- 

 out the Aid of Climbing Boys. 



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