1814.] Philosophical TraJisacfmis, Part II. 181S. 385 



cipal fixed Stars, deduced from Observations made with the Mural 

 Circle at the Royal Observatory. By John Pond, Esq. Astro- 

 nomer Roval, F. R. S. The observations from which this catalouue 

 was drawn up appear to have been made with great care ; and are 

 so numerous, that the distances are certainly made out much more 

 exactly than in any former tables. But from the very nature of 

 such a catalogue, which occupies 20 pages, we are precluded from 

 giving it here. 



15. Observations on the Summer Solstice of 1813, with the 

 Mural Circle, at the Royal Observatory. By John Pond, Esq. 

 Astronomer Royal, F. R. S. The mean obliquity of the ecliptic 

 comes out from these observations 2'6° 27' 49-5". The mean obli- 

 quity at the summer solstice, 1812, was 23" 2/' 50-5", and at the 

 winter solstice, January 1st, 1813, it was 23° 2/' 50 0". 



Article X. 



Proceedings of Philosophical Societies. 



ROYAL SOCIETY. 



On Thursday, the 24th March, a paper by Thomas Young, M.D. 

 Foreign Secretary to the Royal Society, on the ne^v structure of ships 

 proposed by Mr. Seppings, was read. Dr. Y. began by obsei;ving, that 

 the advantage of the oblique position of the beams and riders had 

 been long known to men of science, and that various unsuccessful 

 attempts had been made to introduce that position into ship build- 

 ing. He then calculates the strain upon ships of war from the 

 length and weight, and the action of the waves. He shows that 

 the oblique position of the beams and riders does not add to the 

 total strength ; but that it b an improvement, on account of the 

 additional siiftViess and inflexibility which it affords. He examines 

 the dififerent alterations made by j\Ir. Seppings, and points out those 

 which he considers as improvements, and tliose respecting the ad- 

 vantage of which he is doubtful. Though, from the clearness and 

 precision with which this paper was written, it would be easy to 

 give a pretty full analysis of it, 1 am induced to abstain from pro- 

 ceeding any farther, from an apprehension that the analysis would 

 scarcely be understood without a more detailed account of Mr. 

 ^leppiiig's paper than I was able to give fronj hearing it read. 



On Thursday, the 31st March, a paper by Mr. Groombridgc was 

 read, containing additional observations on atmospherical refrac- 

 tion. In his former paper he had confined his observations to stars 

 not more than 7^^° tVom the zenith. He has since gone a good 

 deal farther. The result is, that Bradley's formula, with certaia 

 alterations in the value of some of the quanviies, will apply to all 

 •tars not more than Hi>° from the zenith, but beyond that distance a 

 new formula is necessary. 



Vol. III. 1^° V. ' 3 B 



