Astronomical Society. 



239 



which they were visited, together with the numher of series of ex- 

 periments made at each place, and the pendulums employed at each 

 station. It should here be, however, stated that the iron and copper 

 convertible pendulums were each furnished with two knife-edges 

 (^respectively marked A and B) ; so that, in fact, Capi. Foster might 

 be considered as having six independent and invariable pendulums, 

 whose results might be compared with each other. The stations 

 that are marked with an asterisk are those which were visited also by 

 Capt, Sabine, in his voyage of experiment in the years 1822 and 1823. 



The whole number of series therefore was 1017 ; and as each series 

 consisted (on an average) of 10 coincidences, the total number of 

 coincidences taken by Capt. Foster was upwards of ten thousand : 

 thus forming a mass of observations made in various parts of the 

 globe never before attempted by any individual, and which must 

 have its due weight in all investigations relative to this important 

 inquiry. In the premature death of this young and accomplished 

 officer, the Society has to deplore the loss of a zealous and active 

 votary to science ; and his memory will be long held dear by those 

 who were more intimately acquainted with him in the relations of 

 private life. 



M. Jean Louis Pons was for many years employed at the Obser- 

 vatory at Marseilles ; where, though his means were extremely 

 limited, he became universally known for his steady attention to the 

 discovery of comets : an attention which procured him the medal of 

 this Society. In the summer of 1819, Her Majesty Maria Louisa, of 

 Bourbon, entered into a correspondence with Baron de Zach re- 

 specting the endowment of a first-rate observatory at Lucca ; de- 

 siring him to solicit an astronomer of known eminence to preside. 

 Three names were immediately suggested ; Encke, Littrow, and Pons: 

 and as the two former had received appointments in their own coun- 

 tries, the choice fell on the latter. In the mean time the Baron had 

 repaired to Lucca, in order to select the site and direct the erection 

 of the required edifice. It was 100 feet long, by 30 in breadth, in- 



