Mr, W. Galbraith on some Astronomical Methods, Sfc. 341 



Article V. 



On some Astronomical Methods of Observation, By William 

 Galbraith, A.M., Teacher of Mathematics, Edinburgh. 



{Concluded from page 194.) 



The following pages contain the methods of registering the 

 indications of the level. The first is that generally adopted 

 by the French mathematicians, such as M. Puissant, and 

 the other the method practised by the writer of this paper, 

 which he thinks more simple, and is that employed in the 

 preceding example, the first instance so far as he is aware 

 of the obliquity of the ecliptic, being determined at Edin- 

 burgh, and that to a very great degree of accuracy by 

 observation. In these means no errors or discrepancies 

 amount to more than one-third of those in Rumkers obser- 

 vation of the latitude of the observatory of Paramatta, 

 under Sir Thomas Brisbane, where it is stated, in Phil, 

 Mag,, vol. i. new series, p. 302, that differences to the 

 amount of 15" are to be found between observations on /3 

 Argus and those on the solstices and Zodiacal stars. See 

 also the Brisbane Catalogue of Stars just published. 



Method of M. Puissant, Traite de Geodesic, T.I. p. 165. 



Somme des a — — 8 



Somme des h = — 8*5 



Inclination du axe de rotation = —r. — = — 0*825 



2 n 



Factem constant, 11*51 



Product ou correction du niveau = — 9"*50 



