Memoir of the Life and Writings qfM. Piazzi. 195 



azimuth circle, and divided with all the precision for which 

 Ramsden was so celebrated. In order to expedite its com- 

 pletion, he attended every day the workshop of that artist ; 

 but finding that the work advanced very slowly, he conceived 

 the idea of stimulating Ramsden, through the medium of his 

 love of reputation. He therefore addressed a letter to Lalande, 

 in which he gave an account of the life and works of the Eng- 

 lish optician. The scheme happily succeeded; Ramsden 

 wrought with unwearied zeal, and our author had the satis- 

 faction of witnessing the completion of his principal instru- 

 ment. He obtained also a transit instrument, a sextant, and 

 some other instruments of secondary importance. The ex- 

 cise-office is said to have claimed a duty on the exportation 

 of the circle, on the ground that it was an English invention, 

 but the claim was speedily abandoned, as Ramsden main- 

 tained, that whatever novelty there was in the instrument, was 

 due to the Italian astronomer, whose instructions he had im- 

 plicitly followed. Piazzi accompanied his instruments to 

 Sicily, where he arrived with them in safety, at the end of 

 1789. 



After the destruction of the observatory of Malta by fire, 

 in 1789, the observatory of Palermo was the most southerly 

 in Europe. The observations made in it, therefore, possessed 

 a peculiar interest, which was in no small degree heightened 

 by the excellence of its instruments, and the activity and skill 

 of their possessor. 



An account of the observatory of Palermo was published 

 by our author in 1798, under the title of Delia specola astro- 

 nomica de regi studi di Palermo. 



When he was thus established in the midst of his instru- 

 ments, Piazzi devoted himself to the construction of a new 

 catalogue of the fixed stars, which he justly considered as the 

 true basis of astronomy. Francois Lalande, Cagnoli, Zach, 

 and others, had undertaken works of the same kind, but they 

 were of too limited a nature, and were founded on the positions 

 of the thirty-six stars which Maskelyne had pointed out to 

 astronomers, as sure points of comparison. Piazzi, on the con- 

 trary, resolved not to trust to the results of single observa- 

 tions, which might be affected by any inaccuracy on the part 



