

CONTENTS. 
—=>>—— 
NOTICES AND ABSTRACTS OF MISCELLANEOUS 
COMMUNICATIONS TO THE SECTIONS. 
MATHEMATICS AND PHYSICS. a 
/ P. 
Mr. J.C. Apams on the Application of Graphical Methods to the Solution of sr 
a 
certain Astronomical Problems, and in particular to the Determination of 
the Perturbations of Planets and Comets............cscsccececsseeeeeceeees Beencietene 
Mr. Henry Buvunt on a Model of the Moon’s Surface............. ane eaapeaenine ces 
Sir W. Hamizton on some new Applications of Quaternions to Geometry .., 
Mr. J. P. Jouve on the Heat of Vaporization of Water............eecesesssees Hpncee 
Rey. Prof. PowExu on De Vico’s Comet .........000008 Seagcanscdscmevssse’sevopes rte 
on a new Equatorial Mounting for Telescopes ...... Rose 
Mr. Rosert Rawson on the Friction of Water.......cscssessrseeceereeee srartngrares 
on Elliptic Integration........,...s006. ResnsccanseeenaerGe trae 
on the Oscillations of Floating Bodies ............scsceseee 


_ Sir Davin Brewsrer’s Description of'a Binocular Camera............sseceeeeeees 

——————— Improvement on the Photographic Camera ............ 
on a new form of Lenses, and their Application to the 
Construction of two Telescopes or Microscopes of exactly equal Optical Power 
Notice of Experiments on Circular Crystals ............ 
Additional Observations on Berkeley’s Theory of Vision 
— Account of a new Stereoscope......... aebabeas a oeccneserste 
Lorp Brovenam’s Experiments on the Inflection of Light.........ssssssssseeeees 







_ Mr. J. A. Broun on the Diurnal Variation of Magnetic Declination and the 
Annual Variation of Magnetic Force...,..ecesesesseseees wis hiedeeb ad side zhials aRev e dee 
_ Rev. H. M. Grover on an Orbitual Motion of the Magnetic Pole round the 
Beem bole of the Earth, osjapenaatl ded qasnick ic dia lotavn'nwats «isi ab tdeobbabacs cote cates 
Rev. Prof. Powziu on some recent Discussions relative to the Theory of the 
SME CL LTTE. sanisas Uaianssaanplpencninsohesnpnaiancestavéeiaoat PAT Lee Fey 
On Irradiation......ccssssseeee Rabie at Sits aati obs pub asnceatak aah a= 
Professor Sroxes on a Mode of Measuring the Astigmatism of a Defective Eye 
on the Determination of the Wave Length corresponding with 
evammintiof. the Spectrimn .aciaacltacshdeeiesicceiisssd.vsenpens os exes ace'es Lawes 
Professor Wurarstrone on Professor Quetelet’s Investigations relating to the 
Electricity of the Atmosphere, made with Peltier’s Electrometer ...........0e+« 


—_—. 

feet. WR. Brer on Shooting Stara vdessesss-sidessecessocesssensocsdctesecoastuasisunees 
_ Mr. Georee Buist’s Meteorological Phenomena observed in India from 
January to May 1849 (communicated by Colonel Sykes) ...:ssssessesseesoessees 
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