422 TRANSIT OF VENUS, 1874. KERGUELEN ISLAND. OBSERVATORY BAY. 



OBSERVATIONS of the TRANSIT of VENUS, 1874, December 8, by the 

 Reverend S. J. PERRY, with the 6-inch Equatorial. 



The double-image micrometer, with power slightly over 150, with an 

 achromatised wedge of dark glass and the negative eye-piece, power 150, 

 with two dark glasses were conveniently placed ; and two other wedges of 

 neutral-tint glass -one very light, the other dark were at hand in case of 

 need. 



The driving-clock of the Equatorial being very inferior, and having no 

 efficient regulating gear, it was necessary to add a new driving power to 

 assist the clock, and to fit a regulating rope to the new driving weight. 

 This was done very effectively by the Rev. W. Sidgreaves. 



Lieutenant Gamble, R.N., arrived from H.M.S. Volage at 6 a.m., and we 

 at once examined the time required for altering eye-pieces, focussing, &c. ; 

 this was about 30 s . 



The morn had been very fine, but the clouds were thickening fast. 

 Unfortunately a dense cloud settled just over the Sun for about 20 minutes, 

 and there was scarcely a breath of wind to move it. 



It was impossible to use the double-image micrometer until Venus was 

 well on the disk, and even then the images were faint without any dark 

 glass.* The wind was rising, and this, combined with the faintness of the 

 light through the clouds, rendered the use of the micrometer at Egress quite 

 out of question. 



The times given below are those given by Dent 2011 uncorrected : 



12 h . O m . 56 S> 5. Venus half on the disk ; solar prism and negative eye- 

 piece, power 150. 



15 h . 40 m . 38 s- 8. A good geometrical contact ; solar prism, power 150 ; 

 no dark glass. There was no appearance of black 

 drop before contact, but this might have been due 

 to the obscuring clouds. 



* The few micrometer readings obtained cannot be utilized. 



