le^ Royal Society. 



sion for the vertical elevation of a particle at the surface. This ex- 

 pression supposes the canal unlimited at the end farthest from the 

 sea. If the canal be stopped by a barrier, the expression changes its 

 form. The formulae obtained by the author enable him to explain 

 a circumstance, hitherto perplexing, namely, that the age of the tide 

 is different as inferred from the height of the high water, or from 

 the time of high water ; being always greater in the former mode of 

 estimation. 



3. " Register of Tides, observed at Coringa, from January 1st to 

 June 30th, 1841." 



4. "Meteorological Journal, from the 20th April 1840 to the 

 29th April 1841. Kept at the Falkland Islands on board H.M. 

 Ketch, Arrow." 



5. " Daily Therraometrical Observations at Cape Palmas, for May 

 1841." 



These last three papers were communicated to the Society by the 

 direction of the Lords Commissioners of the Admiralty. 



November 30, 1841. — Anniversary Meeting. The following are 

 extracts from the Report of the Council. 



Awards of Medals. 

 The Council has awarded the Copley Medal for the present year 

 to Dr. G. S. Ohm, of Nuremberg, for his researches into the laws 

 of Electric Currents, contained in various memoirs published in 

 Schweigger's Journal *, Poggendorff's Annalen, and also in a sepa- 

 rate work, entitled Die Galvanische Kette Mathematisch Bear- 

 bitet\, published at Berlin in the year 1827. In these works. Dr. 

 Ohm has established, for the first time, the laws of tlie electric cir- 

 cuit ; a subject of vast importance, and hitherto involved in the 

 greatest uncertainty. He has shown that the usual vague distinc- 

 tions of intensity and quantity have no foundation, and that all the 

 explanations derived from these considerations are utterly errone- 

 ous. He has demonstrated, both theoretically and experimentally, 

 that the action of a circuit is equal to the sum of the electro-motive 

 forces divided by the sum of the resistances ; and that whatever be 

 the nature of the current, whether voltaic or thermo-electi'ic, if this 

 quotient be equal, the effect is the same. He has also shown the 

 means of determining with accuracy the values of the separate re- 



* 1. Oa the electric conductibility of the metals. (Schweigger's Journal, 

 second series, vol. xiv.) 



2. Experiments to discover the power of electro-magnetic multipliers. 

 (Ibid. vol. XXV.) 



3. Researches to ascertain the nature of unipolar conductors. (Ibid. vol. 

 xxix.) 



4. On hydro-electric currents. (Ibid, third series, vol. iii.) 



5. Statement of facts desti-oying the relations which have been confu- 

 sedly established between several galvanic properties, and particularly 

 hydro-electric conductors. (Ibid. vol. v.) 



G. Theory of galvanic cun-ents. (Ibid. vol. vii.) 



[t A translation of this work will be found in Taylor's Scientific Me- 

 moirs, vol. ii. — Edit.] 



