l CONTENTS. 



Page 



A Mode of Regulating the Supply of Water between Intersecting 

 Rivulets and Canals. Devised by the late ROBERT ALMOND, 

 Esq., of Nottingham. [Communicated by MARSHALL HALL, 



M.D., F.R.S.E., &c.] 307 



On the Geometric Properties of the Magnetic Curve, with an Ac- 

 count of an Instrument for its .Mechanical Description. By 



P. M. ROGET, M.D., Sec. R.S 311 



On the First Invention of Telescopes, collected from the Notes and 

 Papers of the late Professor Van Swinden. By Dr. G. MOLL. 319 



Proceedings of the Royal Institution .... 333 



ANALYSIS OF BOOKS. 



Philosophical Transactions of the Royal Society of London, for the 

 year 1830. Part II. . . . . . .337 



Life of Sir Humphry Davy, Bart., LL.D., late President of the Royal 



Society, &c. By John Ayrton Paris, M.D., F.R.S. . .347 



Plantae Asiaticae Rariores ; or Descriptions and Figures of a select 



Number of unpublished East India Plants. By N. Wallich, M.D. 360 



A Numerical List of Dried Specimens of Plants in the East India 

 Company's Museum, collected under the Superintendence of 

 N. Wallich, M,D ibid. 



FOREIGN AND MISCELLANEOUS INTELLIGENCE. 

 I. MECHANICAL SCIENCE. 



1. On the Discharge of a Jet of Water under Water (R. W. Fox, Esq.) 368 



2. On preventing the Discharge of a Bullet from a Gun by the Finger ibid. 



3. Clement's Experiment Easy Mode of repeating it . . . 369 



4. Browne's moving Molecules ..... ibid. 



5. Exact Measure of a Degree ... . 370 



6. Svanberg on the Temperature of the Planetary Space . . ibid. 



7. On the Relation between the general Direction of the Stratification of 



the Earth and the Lines of equal Magnetic Intensity in the Northern 

 Hemisphere (M. L. A. Necker) . . .372 



8. Force of Terrestrial Magnetism . .374 



9. An Acoustic Rainbow . . . 375 



