PREFACE. 



Cooper, Englefield, Delafons, Sheldrake, Capper, Ark- 

 wright. For the various and important objects of their re- 

 search, he must refer to the Table of Contents, the ample 

 Index, and the other assistant indications he has been sedu- 

 lous to present to the Reader. 



This Volume contains sixteen Copper Plates, illustrating 

 nineteen distinct objects : viz. Herschel's discoveries of the 

 Structure and Changes of the Sun. 2. Various circular In- 

 struments for measuring Angles, 3, 4. Two Hydraulic En- 

 gines invented by Mr. Close for raising water above its Level 

 by the Syphon. 5. Method of making Gun Flints. 6. Mr. 

 Cooper's Designs to shew by the structure of the Ear, that 

 a species of Deafnefs may be cured by puncture of the 

 Membrane of the Tympanum. 7. Loysel's new Appara- 

 tus for bleaching Paper. 8. Carangeau's Instrument for 

 measuring Crystals. 9. Dr. Thomson's Apparatus to shew 

 that the Rumfordian Circulation of Solids in Fluids is not 

 occasioned by Currents. 10. Volta's Sketches in support 

 of his Theory of Galvanism. 11. Trevithack's new and 

 powerful Engine for producing Mechanic Force by an in- 

 cluded Column of Water. 12. Mr. Murray's Apparatus 

 for new Experiments on the conducting Power of Fluids. 

 13. Dr. HerscheFs Apparatus for viewing the Sun through 

 Fluids. 14. Mr. Hornblower's Hydraulic Bellows for a 

 Forge. 15. Rev. Wm. Pearfon's Projection of the Orbits 

 of the Earth and of the new Planet Ceres, 16. Mr. Mur- 

 ray's Apparatus for shewing the conducting Power of Mer- 

 cury and of Oil in a Veffel of Ice. 17. A simple and free 

 Efcapement for Time Pieces, by Mr. Delafons. 18. Mr. 

 Arkwright's Engine for raising Ores from Mines. And, 19. 

 A cheap, simple, and accurate perspective Instrument, by 

 Richard Lovell Edge worth, Esq. 



With prospects already fo animating, under the favora- 

 ble circumstances of a general Peace, and the facilities it 

 affords to philosophical pursuits and manufacturing inven- 

 tions, it is to be expected that the value of our communi- 

 cations and discoveries will increase. 



Spho Square, London, May 1, 1802. 



