CONTENTS. 



FEBRUARY, 1807. 



Engravings of the following Objects: 1. An expanding Wheel for driving Ma- 

 chinery, by Mr. Flint; 2. A new Door Lateh, by Mr. Antis ; 3. An improved 

 Book Case Bolt, by Mr. Herbert ; 4. An Expansion Balance invented by 

 Mr. Hardy. 



I Account of a Fact, not hitherto observed, that the Galvanic Power heats Water 

 while decomposing it in Part. In a Letter from Mr. John Tatum, Jun. 81 



U. Account of the Discovery of the Means of illuminating by the Gas from 

 Coal, by Dr. Clayton, previous to the Year 1 664, In a Letter from Mr. John 

 Webster, --__._ 33 



III. Observations on the Metallic Composition of the Specula of reflecting Tele- 

 scopes, and the Manner of casting them ; also a Method of communicating to 

 them any particular Conoidal Figure; with an Attempt to explain, on 

 Scientific Principles, the Grounds of each Process, and occasional Remarks 

 on the Construction of Telescopes. By the Rev. J. Little. - 84 



IV. On the Absorption of Electric Ligh^ by different Bodies, and some of their 

 Habitudes with respect to Electricity. In a Letter from Mr. William Skrim- 

 shire, Jun. ----,. 20I 



V. Observations upon the Marine Barometer, made during the Examination of 

 the Coasts of New Holland and New South Wales, in the Years 1801, 1802, 

 and 1803. By Matthew Flinders, Esq. "- - - 107 



VI. Letter from a Correspondent, on the Exliibition of the Invisible Giri. 1 19 



^^i' description of a new permanent Compensation-Balance for a Time-keeper. 

 By Mr. W. Hardy. ----- 120 



VIII. Description of an expanding Band Wheel to regulate the Velocity of 

 Machinery, By Mr. Andrew Flint. - - - 126 



J^- Account of a Discovery of Native Minium. In a Letter from J. Smilhson. 

 Esq. F. R. S. to the Right Hon. Sir Joseph Banks, K. B. P. R, S. 127 



X. Account of a new semi-metallic Substance, called Menacane, and its Ores. 

 By the late G.Mitchell, M. B - - - . jgg 



XI. On the Cultivation of Grapes. By G. Cumberland, Esq. - 140 



XII. Useftil Notes and Observations respecting the Llands of Orkney and Shet- 

 land, By Patrick Neil, A. M. - - - 1 145 



XIII. Description of a very useful Bolt for Bookcase Doors. By Mr. P, Herbert. 



154 



XIV. Description of an improved Door Latch. By Mr. Jolm Antis. 155 



XV. ScientificNews:— Method of preventing \^'et from being introduced into 

 Rooms by Wmdows which shut together like folding Doors, 150— Extempo- 

 raneous Prmtmg Press, used by Country Comedians, 157— Art of Printing 

 from Designs upon the Surface of Stone, 158-Gilding by Means of Zinc! 



.,7~^^^^'^ °^ *"^ famous John Harrison, which does not require cleanino- 13y 

 — loCorrespondents, leo. '^' 



MARCH. 



