THE 



PHILOSOPHICAL MAGAZINE, 



OR 



ANNALS 



OF 



CHEMISTRY, MATHEMATICS, ASTRONOMY, 



NATURAL HISTORY, AND 



GENERAL SCIENCE. 



BY 



RICHARD TAYLOR, F.S.A. F.L.S. M.Astr.S.&c. 



AND 



RICHARD PHILLIPS, F.R.S. L.&E. F.L.S. &c. 



" Nee aranearum sane textus ideo melior quia ex se fila gignunt, nee noster 

 vilior quia ex alienis libamus ut apes." Just. Lips. Monit. Polit. lib. 1. cap. 1. 



VOL. IV. 



NEW AND UNITED SERIES OF THE PHILOSOPHICAL MAGAZINE 

 AND ANNALS OF PHILOSOPHY. 



JULY— DECEMBER, 1828. 



LONDON: 



PRINTED BY RICHARD TAYLOR, RED LION COURT, FLEET STREET : 



AND SOLD BY LONGMAN, REES, ORME, BROWN, AND GREEN ; CADELL ; BALDWIN 



AND CRADOCK J SHERWOOD, GILBERT, AND PIPER J SIMPKIN 



AND MARSHALL; UNDERWOOD; W. PHILLIPS; HARDING; 



HIGHLEY, LONDON : — AND BY ADAM BLACK, 



EDINBURGH ; SMITH AND SON, GLASGOW ; 



AND HODGES AND M'ARTHUR, 



DUBLIN. 



