ADVERTISEMENT. 



A new EleQrical Instrument, by Mr. Wilson. 3. New Fil- 

 tering Apparatus, by Professor Parrot. 4. Original Blow- 

 pipe, by the Abbe Melograni. 5. Apparatus for Filtration, 

 by Sir H. C. Englefield, Bart, &c. F. R. S. 6. Struaure for 

 purifying an entire Stream of Water. 7. Very simple striking 

 Part of a Clock, by Mr. Prior. 8. An Instrument for count- 

 ing the Number of Draughts from a Mine, by Mr. Antis. 

 9. An Inftrument for delineating in Perspe6tive. 10. Cheap 

 Apparatus for drawing Ovals. 11. Sketch of Mr. Malton's 

 Method of making very large Port-folios for Drawings and 

 Prints. 12. A Lamp for burning Tallow, by Mr. J. W. 

 Boswell. 13. An Evaporating Furnace, by Curadau. 14. 

 A Gripe for the Safety of Carriages, by Mr. Bowler. 15. A 

 perpetual First Mover. 16. A new Parallel Rule. 17. A 

 new Compensation Pendulum, by Mr. Edward Troughton. 

 18. An Instrument for measuring the Absorption of Gases, 

 by Morozzo. 19, Diagram to explain the Galvanic Energy 

 upon Water, by C. Wilkinson, Esq. 20. Two Plates exhi^ 

 biting a Condenser of Force, by which the Aftion of a vari- 

 able First Mover is converted into a constant Pressure, by 

 Prony. 



Soho Square, December, 1804. 



