XXI 



Magnetical Observations at Port Bowen, &c. A.D. 1824-25, compre- 

 hending Observations on the diurnal Variation and diurnal Intensity 

 of the Horizontal Needle ; also on the Dip of the Magnetic Needle 

 at Woolwich, and at different Stations, within the arctic Circle. By 

 Captain W. E. Parry, R.N. F.R.S. and Lieutenant Henry Foster, 

 R.N. F.R.S page 293 



Abstract of the daily Variation of the Magnetic Needle No. 2. By 

 Lieutenant Henry Foster, R.N. F.R.S 293 



Observations for determining the Dip of the Magnetic Needle. By 

 Captain W. E. Parry, R.N. F.R.S. and Lieutenant Henry Foster, 

 R.N. F.R.S 293 



Observations on the diurnal Changes in the Position of the Horizontal 

 Needle, under a reduced directive Power, at Port Bowen, 1825. By 

 Lieutenant Henry Foster, R.N. F.R.S 293 



A Comparison of the diurnal Changes of Intensity in the Dipping and 

 Horizontal Needles, at Port Bowen. By Lieutenant Henry Foster, 

 R.N. F.R.S 293 



Account of the Repetition of Mr. Christie's Experiments on the Mag- 

 netic Properties imparted to an Iron Plate by Rotation, at Port Bow- 

 en, in May and June, 1825. By Lieutenant Henry Foster, R.N. 

 F.R.S.; together with Mr. Christie's Remarks thereon 293 



Observations to determine the Amount of Atmospherical Refraction 

 at Port Bowen in the Years 1824-25. By Captain W. E. Parry, 

 R.N. F.R.S.; Lieutenant Henry Foster, R.N. F.R.S.; and Lieu- 

 tenant J. C. Ross, R.N. F.L.S 296 



1827. 



Description of a Percussion Shell, to be fired horizontally from a com- 

 mon Gun. By Lieut-Colonel Miller page 296 



On the relative Powers of various metallic Substances as Conductors of 



Electricity. By Mr. William Snow Harris 298 



On the Expediency of assigning Specific Names to all such Functions 

 of simple Elements as represent definite physical Properties ; with 

 the Suggestion of a new Term in Mechanics ; illustrated by an In- 

 vestigation of the Machine moved by recoil, and also by some Ob- 

 servations on the Steam Engine. By Davies Gilbert, Esq. M.P. 

 V.P.R.S. &c 299 



The Croonian Lecture for 1826. By Sir Everard Home, Bart. V.P.R.S. 301 



On a newly discovered Genus of Serpentiform Fishes. By I. Har- 

 wood, M.D. F.L.S 302 



An Examination into the Structure of the Cells of the Human Lungs ; 

 with a view to ascertain the Office they perform in Respiration. By 

 Sir Everard Home, Bart. V.P.R.S 303 



Remarks on a Correction of the Solar Tables required by Mr. South 's 

 Observations. By G. B. Airy, Esq. M.A 305 



On the mutual Action of the Particles of Magnetic Bodies, and on 

 the Law of Variation of the Magnetic Forces generated at different 

 Distances during Rotation. By S. H. Christie, Esq. M.A. F.R.S. 305 



