CONTENTS. 



Power: also, An Account of' an improved Single-leaf Electro- 

 meter,- of the Combustion of Iron by a Jet of Sulphur in Va- 

 pour,- and of an easy Mode of imitating native Chalybeate 



Waters " 2 41 



Further Remarks on the Theory of Parallel Lines ... 246 

 On the Mathematical and Astronomical Instrument Makers at 



Paris. By Lieut. Zahrtmann 252 . 



Suggestions regarding some probable Sources of Error' in the 



usual Modes of ascertaining the Force of Steam . . . 259 



Remarks on an Article published in No. 23 of the Journal of 



Science, and treating of the New Tables of Refraction. Bu 



J. Ivory, Esq. M.A. F.R.S. ........ 261 



Description of a Rotative Thermo-magnetical Experiment. By 



Mr. William Sturgeon 269 



Zoological Notices. % Mr. John Edward Gray '. '. 274 

 Analysis of Professor Hausmann's Essay on the Geology of the 



Apennines # 2~8 



Chemical Examination of Green Feldspar from Beverly, Mas- 

 sachusetts. By J. W.Webster, M.D. .... 283 

 Descriptions of several new Species of Ascidia. By C. A. Le- 



sueur * og. 



Dissection of a Batrachian Animal in a living State. By Ri- 

 chard Harlan, M.D. Professor of Comparative Anatomy to 



the Philadelphia Museum 325 



Remarks on the Theory of the Figure of the Earth. Bu 



J. Ivory, Esq. M.A. F.R.S. 339 



Examination of the Divisions of Reichenbach's Circle at the 



Observatory of Konigsberg. By M. Bessel ... 348 



On Mr. Babbage's new Machine for calculating and printing 



Mathematical and Astronomical Tables. From Francis 



Bajly, Esq. F.R.S. 4- L.S. 355 



A brief Account of some Electro-magnetic and Galvanic Ex- 

 periments. By Robert Hare, M.D. Professor of Chemistry 



in the University of Pennsylvania 357 



On the Circle. By John Walsh, Esq '. 368 



On a Method of finding the Limits of the Roots of the higher 

 Powers of Numerical Equations. By Mr. J. Rowbotham 



369 

 On the Application of the Term "Infinite" .... 372 

 Two Lines from the Nautical Almanac, addressed to Mr. Ivory. 



374 

 An Account of some Experiments made in order to deter- 

 mine the Velocity with which Sound is transmitted in the 

 Atmosphere. By Olinthus Gregory, LL.D., Secretary 

 of the Astronomical Society of London, and Professor of Ma- 

 thematics in the Royal Military Academy at JVoolwich ' 401 



