Vlll CONTF,NTS. 



Page 

 Mr. S. Read on a Decimal System of Monetary Calculation, 

 founded on the present Denominations of Money and Coins 



in Great Britain , 441 



Mr. D. Mushet on the Immersion of Copper for Bolts and Ship- 

 sheathing in Muriatic Acid, as a Test of its Durability .... 4-44 

 Mr. J. O. Westwood. Insectorum nonnullorum exoticorum 



(ex Ordine Dipterortim) Descriptiones 447 



Proceedings of the Royal Astronomical Society 449 



■ Zoological Society 4-52 



Meteorological Observations 468 



Index 469 



PLATES. 



I. An Engraving illustrative of Professor Faraday's Eighth Series of 

 Experimental Researches in Electricity — on the Source of the 

 Electricity developed in the Voltaic Battery. 



II. An Engraving Illustrative of Mr. Nixon's Paper on the Trigonometri- 

 cal Height of Ingleborough above the Level of the Sea. 



ERRATUM. 



Page 88, line 20, and page 89, lines 8 and 12, for sec-chd read sup-chd 

 [supplemental chord]. 



