ASTEONOMICAL OBSERVATORIES. 379 



Miscellaneous observations were made lirst to (lelermiiie tlie latitude 

 and longitude with great accuracy. It is now used principally for iu- 

 Ktruction. 



Tlie plan of this observatory was made and the first instrument 

 oidered in the year 1841. The excavations for the building were 

 commenced in 1813, and three years later observations began. The 

 building is situated on a hill, northwest of the college, commanding a 

 free horizon. It is GO feet long by 30 feet wide, comprising two wings 

 on the east and west sides, and two rooms in the middle, viz : The 

 clock-room and librarj^ besides cellar and dome. 



The west wing has a transit instrument by Ertel & Son, 7 feet long 

 and 4J inches aperture 5 the east wing a meridian circle by Troughton 

 & SIMMS, reading to fractions of a second by four microscopes, with an 

 object-glass of 4 inches clear aperture. The equatorial was also made 

 by TROUGnTON & Simms, has 4.8 inches aperture with powers from 

 25 to 400, clockwork and micrometer, strong mounting and large circles. 

 The dome measures 20 feet in diameter, and was intended for an 8-iuch 

 equatorial, which had been ordered in Paris, but had to be replaced by 

 the present one. Two sidereal clocks, originally mounted in the east 

 and west wings, and a meantime chronometer hy Molyneaux, of Lou- 

 don, a universal instrument by Ertel & Son, a reflecting circle by 

 Troughton & Simms, and two 3-inch telescopes completed the original 

 outfit of the observatory, which, together with the building, cost about 

 $13,000, a small sum compared to the prices of the present day. The 

 expenses were defrayed for the most part by a donation of the Eev. 

 TH03IAS Meredith Jenkins, S. J., of Baltimore. 



The building of the observatory and the mounting of the instruments 

 was superintended by the first director, James Curley, S. J. The 

 geographical position was determined by him in 184G, the longitude by 

 corresponding observations of moon-culminations at Georgetown and 

 Greenwich, the latitude by ui)per and lower culminations of circum- 

 I)olar stars. 



The revolution of 1847 brought several Italian professors to George- 

 town, among whom were De Vico, Secchi, and Sestini. The former 

 had to leave a few weeks later for London on some important business, 

 where he died of typhoid-fever on November 15, 1848, only forty-three 

 years of age; but the gold medal is still preserved here, which he 

 received from the King of Denmark for his discovery of six comets (I, 

 1844; II, 1847; I, V, VI, IX, 184G) while director of the observatory 

 at the Eoman College. He was a member of the Eoyal Astronomical 

 Society of London. 



F. Secchi, then thirty years of age, taught physics for one year and 

 then returned to Rome to enter upon his career in physical astronomy, 

 but his first interest in this study dates from the observations he made 

 with F. Curley at Georgetown. 



F. Sestini began observations of star- colors in 1849, the manuscript 



