ADVERTISEMENT. 



vanic Apparatus, convertible at Pleasure into one or more 

 Plates, 6. Hydraulic Machine operating by the rotation of 

 two Pinions, in a Water Veflel. 7. An improved Jib for a 

 Crane, by Mr. Bramah. 8. New Filtering Apparatus, by 

 Messrs Harman and Dearn. 9. Galvanic Apparatus. 10. 

 An ancient Lock ufed in Egypt and Western Asia for above 

 three thousand Years'. 1 1. Developement of the Mechanifm 

 of the Lock. 12. Sketch of the Orbits of the New Planets, 

 by Jerome de Lalande. 13. Cryftals of Arseniated Copper, 

 by Hauy. 14. Telegraph by the Human Figure. 15. Ma- 

 chine for levelling the Surface of Land, by Mr. David Charles. 



16. Shaded Se61ions of a Clock, which strikes the Hours by 

 simpler Mechanism, and with greater regularity than usual, 

 by means of a Pendulum substituted in the Place of a Fly. 



17. Specimen of a very curious antique Composition or Paint- 

 ing in coloured Glass, by an Art at present lost. 18. Im- 

 proved Lamp for producing a strong Heat in Chemical Ex- 

 periments, by Mr. Accum. 



Sefio Square, Ai(guji, 1804-. 



