114 



The following Gentleman was duly elected an Ordinary 

 Fellow : — 



Dr John Wylie, late Physician-General, Madras, 



The following Donations to the Library were announced : — 



Smithsonian Contributions to Knowledge. Vol. II. Collection of 



Various Reports. 4to. — From the Smithsonian Society, 

 Transactionsof the Zoological Society of London. Vol.IV.,Pt.l. 4to. 

 Proceedings of the Zoological Society of London. Nos. 201-213. 8vo. 

 Proceedings of the American Association for the Advancement of 



Science. August 1850. 8vo. — From the Association. 

 Transactions of the Horticultural Society of London. 2d Series. 



Vol. II., Pts. 3,4, 5,6 ; Vol. III., Pts. 1, 2,3. From the Society. 

 Novi Commentarii Academise Scientiarum Instituti Bononensis. 



Tom. VI., VII., VIII., IX., X. 4to.— i^rom the Academy. 

 Memorie della Accademia delle Scienze dell' Istituto di Bologna. 



Tomo I. 4to. — From the Academy. 



Monday^ 16/A February 1852. 



Mr RUSSEL in the Chair. 



The following Communications were read : — 



1. On some improvements in tlie instruments of Nautical 

 Astronomy. By Professor C. Piazzi Smyth. 



The excessive motion of a ship at sea renders the use of the ordi- 

 nary instruments employed on land impossible, and restricts the 

 sailors to the use of one on the principle of the duplication of images 

 discovered by Hadly. 



The favourite form is at present, and has always been, that of a 

 quadrant or sextant, i.e., a part of a circle, rather than a whole one, 

 though this has often been brought forward by scientific men, and 

 proved to be the most accurate : but the construction of these circles 

 was generally too complicated, and practically unsuited to the circum- 

 stances usually met with at sea. 



Taking the best of the sextants, then, as the form generally found 

 in actual use, the author shewed that it laboured under many disad- 



