CONTENTS. vii 



DECEMBER, 1810. 



Engravings of the following Subjects: I. Apparatus for Experiments on the 

 Sonorous Properties of Gasses, by Mr. F. Kerby and Mr. MeiTick, jun. 2. 

 Crystals of Apophyllite, or Fisheye Stone, by Mr. Haiiy. 3. A new Hygro- 

 meter for G\sses, byMr.Guyton-Morveau. 4. Delineations of Mr. Congreve's 

 Military Rockets 



I. On the Electric Column. By J. A. De Luc, Esq. F. R. S. - 2il 



II. The Results of some Experin-tents on the sonorous Properties of the Gasses, 

 by F.Kerl)Y, and Mr. Merrick, jun. of Cirencester - - 269 



III. "Description of the Apophyllite, Ichthyophthahuite of Dandrada and Reuss, 

 Fischaugenstein of Werner. By xMr. Haiiy - . - 272 



IV. On the Motion of Rockets botli in Nonresisting and Resisting Mediums. 

 By VV. Moore, Esq. ; Communicated by the Author - 216 



V. Remarks on a new Principle introduced by Legendre in his Elements of 

 Geometry. In a Letter from Thomas Knight, Esq. - 285 



VJ. Description of an Hygrometer for Gasses, and the Method of using it, to 

 subject diiTerent Substances to their Action: by Mr. Guyton-Morveau 2S7 



VII. The Crooniaa Lecture. By William Hyde Wollaston, M. D. Sec. R.S. 



289 



VIII. Method of ascertaining the Value of Growing Timber Trees at different 

 and distant periods of Time: by Mr, Charles Waistell of High Holborn 30O 



IX. Remarks on Professor Wood's new Theory of the Diurnal Motion of the 

 Earth round its Axis. In a Letter from a Correspondent - 309 



X. An analytical Essay on the Scammonies of Aleppo and Smyrna, with some 

 Observations on the reddening of Litmus by Resins : by Messrs. Botiillon- 

 Lagrangc and Vogel - - - - - 311 



Scientific News. - - - - » 517 



ileteorolcgical Table. - - • - ^^Q 



SUPPLEMENT 



