66 Scientific Intelligence^ [Jan. 



Peru, as well as in Chili ; and that it is cultivated very abundantly 

 in those countries by the Indians, who call it Papas. 



II. Bemarkable Difference beticeen the Celestial and Terrestrial 



Arc of the Meridian. 



In the year 1808, Baron von Zach determined the latitude of 

 Florence at the Observatory of the Grand Ducal Observatory, 

 and found it bv 506 observations of different stars to be 

 43° 46' 4-3r'. In 1809, he determined the latitude of Pisa by 

 504 observations, made at the Observatory, and found it to be 

 43° 43' 11-77"; so that the difference between the latitude of 

 these two cities is 2' 52-54'". 



Barou von Zach hkewise ascertained the longitudes of these 

 two places, by observations of the occultations of various stars 

 by the moon, and found them as follows : 



Florence, 35' 40-2" in time E. of the Observatory of Paris 

 Pisa, 32 8-0 



In the year 1815, when Tuscany was restored to its legitimate 

 sovereign, Ferdinand IV. the reigning Grand Duke ordered a 

 trigonometrical survey of the whole Grand Duchy to be made. 

 This survey was committed to the care of Father Inghirami, 

 Professor of Astronomy, and Director of the two Observatories 

 of Florence. He conducted it with the greatest possible preci- 

 sion, as may be seen in the three following memoirs, which he 

 published in succession. 



1. Dalla Longitudine e Latitudine delle Citta di Pistoja, e di 

 Prato. Estratta dal vol. delle Memorie di Scienze Matem. 

 e Fisic. dell' Imp. e K. Accademia Pistojese, per I'Anno 1816. 

 Pistoja, 1816. 



2. Delia Longitudine et Latitudine Geografica della Citta di 

 Volterra, S. Miniato e Fiesole. Firenze, 1817. 



3. Di una Base Trigonometrica Misurata in Toscano nell' 

 autunno del 1817, letta in Livorna all' Accademia Labronica il 

 di 7 Febrajo, 1818. Firenze, 1818. 



During the course of this survey, he joined Florence and Pisa 

 together by a series of triangles, and thus was enabled to deter- 

 mine geometrically the difference between their latitudes. Baron 

 von Zach had determined the latitude of Pisa astronomically, 



43° 43' 11-77" 

 Inghirami found it 43 43 19-40 



Difference 00 00 7-63 



This enormous difference, if we were to ascribe it to the 

 operations of Inghirs-mi, would suppose an error of at least 100 

 toises in the geodesiacal operations ; which is quite inadmissi- 

 ble. 



The longitude of Pisa, as found by the astronomical observa- 

 tion* and the trigonometrical survey, was ikewise different. 



