088 REPORTS OF ASTRONOMICAL OBSERVATORIES. 



Feoment. 2. Linear dividing engine by Froment. 3. Lineaj divid- 

 ing engine by Elliott Brothers. 4. Photograpli measuring machine 

 by Grubb. 5. Balance by Oertling. 6. Five 2-meter and one IO- 

 meter bars. Grubb. 7. Two comparator microscopes and long stone 

 table. 8. 10-inch wheel cutting engine ; Swiss. Jenssen & Hensen. 



(j) 1. Sprengel pump C end on and many Geissler tubes. 2. Air- 

 pump and apparatus. 



(/(•) Various photographic apparatus. 



(Z) A large assortment of electrical and electro-magnetical apparatus. 

 One standard and one marine barometer: Negretti & Zitmbra. Vari- 

 ous thermometers. 7-inch spherometer, 1 part = jo J o o inch, to oVo o th by 

 estimation; 4-inch spherometer ; both by Hilger. Arithmometer by 

 Thomas de Colmar; C places. Arithmometer by Thomas de Col- 

 mar; 10 places. Foucault siderostat by Eichens ; 16-inch mirror (and 

 a spare one), silver in glass, by A. Martin. Silbermnnn heliostat by 

 DuBOSCQ. Heliostat by Browning. King's barograph and anemo- 

 graph by Casella. Binocular microscopes by Smith & Beck and 

 Eoss. Polariscope by Ladd ; 10-inch, 6-iuch, and 4-inch induction coils 

 by Aprs. A large collection of cut crystals ; also diffraction appara- 

 tus by SCHWERD. 



The library is now getting to be xqyj large and fairly representative. 

 It i§ rich in early editions of astronomical and mathematical writers. 

 The departments of periodicals and learned societies are good ; the sec- 

 tions of optics and comets are fine. No opportunity of adding to the 

 collection is missed. It has been found necessary lately to provide about 

 500 feet of additional shelving. 



Work done during the past year (1880): 



The work during 1880 has been chiefly cometary and spectrosco[)ic 

 observations with the 15-inch refractor and determination of compari- 

 son stars with the transit circle; Mars was compared with a Orionis 

 and a Tauri with the astrophotometer. 



Some specimens of glass were tested with a spectrometer made from 

 an old alt-azimuth instrument. 



The greater part of the time has been devoted to the reduction of the 

 observations connected with Lord Lindsay's Transit of Venus Expedi- 

 tion. These reductions are now approaching completion. 

 Work proposed for 1881: 



The same class of work is proposed for 1881. 

 Publications : 



Ko considerable works were published in 1880. Various i^apers were 

 communicated to the " Astronomische Nachrichten " ; Monthly Notices 

 of the "Boyal Astronomical Society," and ''Urania," besides which 13 

 special circulars were distributed to all applicants. 



