726 REPOETS OF ASTRONOMICAL OBSERVATORIES. 



distributed would be sufficient to determine the parallax of a star -with 

 a probable error of about ± 0".035. If we coufine ourselves to the obser- 

 vatiou of such stars, the star of comparison of which is neither too feeble 

 or too distant, the observations may be made very rapidly without 

 fatiguing the eye, so that a considerable number of stars can be compared 

 in one night. There are several hundred pairs of stars in the heavens 

 a\'ailable for the purpose, and it does not seem therefore at all imprac- 

 ticable for several observers to take up the matter of settling upon a 

 direct determination of the parallax of stars of the sixth magnitude, in 

 which the probable error would amount to oidy about ± O^'-OOS. The 

 medium parallax of these stars is, according to Peters, O-^.O^T, but prob- 

 ably is only one-half of this. Both magnitudes, as also their difference, 

 are so much above the probable errors that it is to be hoped that con- 

 jectures on this imiiortaut point will, at no distant time, be no, longer 

 necessary. 



Stonyhukst College (near Whalley), England. 

 StonyJiurst College Ohserratory. 



Longitude from Greenwich, 9'-" 52^G8 W. 



Latitude, 53° 50' 40" N. 



Authority for latitude and longitude: Nautical Almanac. 



Directors: A. Weld, 1838 5 



Eev. S. J. Perry, S. J., F. E. S. 

 Assistants: M. M. W. Carlisle 5 



W. McKeon; 



J. Eoonsy; 



J. CULLEN. 



Location : Four miles W. of Whalley, Lancashire, England. Height 

 above sea, 381 feet. Built in 1838 in the park of the Jesuit College. 



IlSfSTRUIVIENTS: 



(a) Meridian circle: by Jones, 2 feet 6 inches; divided to 5'; micro- 

 scopes reading to 1" ; aperture of object glass, 3 inches 5 power generally 

 used, 56. 



{b) Transit Instrument: aperture of object glass, 2 inches |; power 

 generally used, 42 ; by Cary. 



(c) Uquatorial instrutnents : one by Napier, Curry, Troughton «& 

 SIMMS ; aperture, 8 inches; powers from 30 to GOO or 700: one by 

 Jones; aperture, 4 inches, (c) A Cassegrain reflector; aperture 9| 

 inches; two, Newtonian; aperture, 7 inches. 



{d) Spectroscopes : an automatic instrument by Browning, 6 prisms of 

 00°, each used twice, with an half prism, making largest dispersion = 36 

 prisms of 60"^. A large star sj)ectroscope by Simms, 4 compound prisms 

 by Hoffman. A large direct vision spectroscope by Browning. Two 

 smaller instruments by Browning. 



(/) Chronograph: small one by. Breguet. 



{g) Clocks ; two sidereal, mercurial pendulums. 



