CONTENTS. 



Observations on the occasional Appearmice of Water in the Ca- 

 vities of regular Crystals; a7id on the porous Nature ofQiutrtz 

 and other Crystalline Substances, as the probable Cause of thai 



Occurreiice 31ft 



On a neio circular Micrometer 314< 



Mr. P. Taylor on Pyroligneous JEther 315 



On a Lunar Iris, or Rainbow by Moonlight . . . , 317 



Note on Mr. Murray's Paper on the Relation of Acids and 

 Alkalies to Vegetable Colours 319 



On the Measurement of the Progress of an Eclipse of the Moon 



•with a Sextant or Reflecting Circle 329 



Reply to Captain Forman on the Theoiy of the Tides . 335 

 Observations on the Flexure of Astronomical Instruments . 338 

 On Governor Ellis's Discovery oftheAcfion of Cold on Mag- 

 netic Needles 340 



Description of a neia Printing Press 341 



Autumnal Blowing of the Narcissus 343 



Oti the anomalous magnetic Action of hot Iron between the white 

 and blood-red Pleat 343 



On Sviut ill JVhcat 35O 



DescrijJtion o/" Hemipodius nivosus; a new Bird from Africa. 



S53 



A Letter from John Pond, Esq. Astronomer Royal, to Sir 

 Humphry Davy, Barf. President of the Royal Society, rela- 

 tive to a Derangement in the Mural Circle at the Royal Ob- 

 servatory 355 



On the Subside7ice of aqueous Vapow, and its RcjJOse on the 

 Beds of Rivers 357 



Notice of some new Galvanic Exp)eriments and Phanomeria 358 

 On the North Polar Distafices of the principal fixed Stars, de- 

 duced from the Observations made at the Royal Observatory 

 at Greenwich 361 



Experiments on the Alloys of Steel, made with a view to its Ln- 



provement *355, 363 



Mr. Moore on Mr. J. Murray's Communications . . 374 



Inquiry resp)ecting Floods in Dorsetshire 377 



On the Origin of the Blast Furnace 401 



Description of a Life-Boat, built by Subscriptioti at Ipsxvichy 



and stationed at Landguard Fort 409 



On Ihc Mcauiremcnl of Timber lis 



