m 10 CORRESPDNDENTS. 



^ The Communication from Mr. J. A is qtiite inadmissible. 



^M It does not contain nor profess to contain any one scientific fact.' 

 f^ The fhilosophical Magazine cannot record mere protests, how- 

 Ail ever laudable the motives which may eive rise to them. Were 

 ."I we to do it, we should have hundreds of them monthly. 



% 



^1 *:(.* Communications for this Work, addressed to the Editor, 



M Pickett- Place, Te;»ipls Bar, will meet with every attention. 





'^Jt^^'^fWW^^'^^^^FW^f^^ 



ENGRAVINGS. 



Vol. XLI. Pepys's Mercurial Voltaic Conductor — Leslie's Dif-. 

 ftrential Thermometer. — Diagrams to illustrate Dr. Wollaston's Pcri- 

 tcopic Camera Obscura and Microscope. — Count Rukifoxd's improved 

 Coffee-pots.— -Mr, .Gosa's Instrument to work Addition of Numbers 

 with Accuracy and Dispatch. — Mr. Dav-is's hanging Scaffold; and 

 Mr. Martin'p Method of relieving a Korse from a Cart when fallen 

 dov/n in its Shafts. — A Quarto Pla!3 to illustl-ate Mr. .7. Hicks's Ac- 

 count of the Situation and Means of raising the Royal George.-*-A Plate 

 to illus.rate Mv. Southerk's Essay on the Equilibrium of a Combination 

 of Beami, Blocks, &c. and on the Polygon of Forces.— -A Plate, to illustrate. 

 Mr. Steevens's Account of a Meteor seen at London and other Places in 

 March last. — A Plate to illustrate Mr. Mac hell's Annular Saw. 



Vol. XLI I. A Plate containing Professor Leslie's Atmometer, ai^!,y 

 Figures to illustrate Dr. Wollaston's Paper on the elementary Particles 

 of certain Crystals. — A Sketch of that Part of the Island of Java which 

 contains vhe natural Lake of Sulphuric Acid. — Interior of Volcano in the 

 Island of Java, and Figures to illustrate Mr. Vv'^alker.'s Paper on the Elec- 

 tric Fluid. — A Plate to illustrate M. Link's Memoir on the Anatomy of 

 Plants, and Dr. WoLL AS ton's Cryophorus. — A third Plate to illubtrate 

 'M. LiNic's Memoir on the An domy of Plants. — Mr. T. JoNEs'is Secto- 

 graphs,— .anew Instrument for dividing right Lines into^qoal Part!,measur- 

 gr&in Angle and ioscribihg Polygons in the Cirtie, &c. 



Vol. XLIII. A Plate to illustrate a New Transit Instrument invented 

 by Sir H. C Ekglefield, Bart. — A Plate to illustrate the Use of Air- 

 ' Vessels in Plants. By Mrs. 1bbetso;<. — A Plate to illustrate M. Se- 

 MENTiNi's new Apparatus for producing Oxygen Gas to restore sus- 

 pended Animation — Mr. Reade's Paper on the Refraction of the Solar 

 .Rays — and Mr. Hargreaves's Observ.ations on Colours. — A Plate to 

 illustrate Mr. J. Whitford's mechanical Substitute for Leeches; and Mr. 

 J. Tilley's Hydro-pneumatic Blow-pipe. — A Plate to describe Mr^ 

 R. Hughes's Gudgeon for the Shaft of a W.ater- wheel ; and Mr. Pad- 

 bury'e Guard for a Carriage-wheel. — A Plate to describe Captain Peat's 

 Temporary Ship's Rudder. — ^A Quarto Plate of Mr. Samuel Jones's 

 8ofa Bed. 



