PREFACE. 



8. Dr. Woflaston's Figures to explain the oblique Refraction 

 of Iceland Crystal. 9. Mr. Dalton's Sketches of the Rivers 

 of England and Wales, and the Districts which supply them 

 with Water. 10. Figure to illustrate Mr. Gough's Theory 

 of sonorous Undulation. 11. The Craniognomic System 

 of Dr. Gall. 12. An Instrument for extracting hard Bodies 

 out of the GEsophagus. 13. A new Reflecting Quadrant 

 by Mr. Ez. Walker. 14. Mr. Huddlestone's Method of 

 floating Boats from one Level to another, without Lofs of 

 Water. 15. Engine Sfolf^blofwing up the Stumps of Trees, 

 by Cit. Saint Victor; and 16. Two Drawings of a Magazine 

 Pistol, which discharges Nine Balls in Succession, by once 

 loading. 



Soko Square, April 28, 1802. 



