CONTENTS. 
iii 
Art. XXTII. Historical Account of Discoveries respecting the 
Double Refraction and the Polarisation of 
Light. (Continued from Vol. IV. p. 130.) 
Period III. Containing the Investigations 
of Beccaria, Martin, Haiiy, Wollaston and 
La Place. 
Sect. III. Account of the Experiments of Mr Ben- 
jamin Martin, - - 150 
XXIV. On the Construction of Polyzonal Lenses and 
Mirrors of great magnitude, for Light-houses 
and for Burning Instruments, and on the For- 
mation of a great National Burning Apparatus. 
By David Brewster, LL. D. F. R. S. & Sec. 
R. S. Edin. - - • 160 
XXV. Account of the recent successful Ascent of Mont 
Blanc by Mr F. Clissold, - 169 
XXVI. On the Visible Solar and Lunar Eclipses which 
will happen in the year 1823, as calculated 
for Edinburgh, by Mr George Innes, Aber- 
deen, - - - 174? 
XXVII. Celestial Phenomena, from January 1. to March 1. 
1823, calculated for the Meridian of Edin- 
burgh, Mean Time. By Mr George Innes, 
Aberdeen, - - - 1 78 
XXVIII. Proceedings of the Royal Society of Edinburgh, 179 
XXIX. Proceedings of the Wernerian Natural History 
Society, - - - - 180 
XXX. Scientific Intelligence, - - 183 
I. NATURAL PHILOSOPHY. 
Astronomy. 1. Second Comet of 1822. 2. Longitude of New 
York, - - fb. 
Optics. 3. jBauman’s Dynameter for Measuring Magnifying 
Powers, - _ p 0o 
Magnetism. 4. Magnetism of the Violet Rays. 5. Stein- 
hauser’s Method of Making Artificial Magnets, - 183 
Acoustics. 6. Velocity of Sound. 7. On Sounds excited in 
Hydrogen Gas, - - - 183,184 
Meteorology. 8. Mr Anderson’s New Atmometer. 9. Sin- 
gular Storm at Enghien. 10. Enormous Fall of Rain in the 
Tropics. 11. Great Dryness of the Air at Perth, 185-186 
Hydrodynamics. 12. New Steam-Engine of great Power, 186 
