Ψ 
CONTENTS. 
NOTICES AND ABSTRACTS OF MISCELLANEOUS 
COMMUNICATIONS TO THE SECTIONS. 
MATHEMATICS AND PHYSICS. 
MatTHEMATICS. 
Tue AsTRONOMER RoyAL on a Question of Probabilities which occurs in the 
use of a fixed Collimator for the Verification of the Constancy of Position of 
PP σι PATS ἢ OAT CICI: act sFasatdd daaseonsa¢cscass cancesantnnaasdisyapcicieveren ae «isos Sele 
Sir W. R. Hamriron on Polyzones inscribed on a Surface of the Second Order 
Mr. W. J. Macquorn ΒΑΝΚΙΝΕ on the Laws of the Elasticity of Solids ...... 
. Lieut, Heat, Evectrricity, MaGnertism. 
Mr. Samuex Beswick on a Method for computing Magnetic Charts of Decli- 
οὐ τοι Sede: op ὙΦ ΤΈΡΕ  ὙὙΓΤ cs sees aaees tenon «panne ads Memes oaeahs th axabeinay nei ce 
Sir Davip BrewsrTEr’s Notice on the Artificial Magnets made by M. Logeman, 
Optician at.Haerlem, by the process of M. Elias............cssssesseeeececeenenees 
----------------- on a New Membrane investing the Crystalline Lens of 
on the Optical Properties of the Cyanurets of Platinum 
and Magnesia, and of Barytes and Platinum ............... macs ods Bat a eee 
on the Polarizing Structure of the Hye ...........seseeeeeee 
on some new Phenomena in the Polarization of the 
FRAP UV aumacidese'ecscesoanah ste da dua οὐ 50.» stteeeeeecseeeeens seteereeeenees steeteseneaanene 
Mr. J. A. Broun on the Effect of Height on the Diurnal Variation of the 
Horizontal Complement of the Magnetic Force............scesssceceeeececeececeees 
———_———_ on the Variation with Season of the Differences of the Mean 
on the Effect of Height in the Atmosphere on the Diurnal 
Variation of Magnetic Declination ........-.0...scsescsccssssusccccesecncecscscscscees 
—— on the Mechanical Compensation of the Bifilar ani Balance 
Magnets for Variations of the Magnetic Moment with Temperature........... 
on the Construction of Silk Suspension Threads for the 
Werraitan, Mar netometer’ <oscs:asecestes <yaeronsswesn sh ον ον cuales σεν σῶς vareanbebase 
M. Cravper on a New Instrument called the Dynactinometer for comparing 
the Power of Object-Glasses, and for ee the ee of the Pho- 
τ τ ἘΠ ec ce Sous caw anieee daca ss <ndsss'ssavecsaveWs on oucsacesdvecesanectecas 
Professor Puriitps’ s Report of a Committee appointed to examine the Effects 
τὰν by Lightning on a Tree near Edinburgh ............:.seeeeeesseeeeeeeers 
on Isoclinal Magnetic Lines in Yorkshire ............. ἈΣΒΑΒ ΑΙ Σ 
Prof. Bases PowE tt on the Refractive Indices of several Substances........... 
Rev. J. B. Reape on a New Solid Eye-piece............+. tes 10. υ waar anna eS 
Mr. Ricnarp Roserts on the Expansion of Solids by Heat...........02ssseseeees 
Professor Stokes on the mode of Disappearance of Newton’s Rings in passing 
the angle of total Internal Reflexion ..................- Ἔρος ΡῈ Hee 
on Metallic Reflexion ....... Ren tcccu casera va weleecesenens ses 
— on a Fictitious Displacement of Fringes of Interference...... 
OF ald Per se DESPRE ark ape beh. nsaehar -enernceeesadvackaceen 
. Professor Srevecty’s Attempt to explain the occasional distinct Vision of 
_ Rapidly Revolving Coloured Sectors...... sanssevacrocceeese accascndeN σα ἘΝῚ tame 5a ae 
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