PERRY'S AND SIDGREAVES' OBSERVATIONS OF THE TRANSIT. 



423 



I tried the micrometer again for the measurement of cusps, but the light 

 was too faint. 



15 h . 56 m . 3 s . Venus half off the disk. Solar prism, power 150 ; the 

 light end of the neutral-glass wedge used. The limb 

 of the Sun was very well denned, and the limb of 

 Venus did not appear to be irregular. 



16 h . 11. 25 S> 8. External contact; solar prism, power 150. Possibly 

 a little too early. 



S. J. PERRY. 



COMPARISONS of the CLOCK Dent 2011 with the TRANSIT-CLOCK, by the 

 intervention of the MEAN SOLAR HALF-SECONDS CHRONOMETER Frodsham 

 3178 ; 1874, December 8. 



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



Reverend W. SIDGREAVES. 



The instrument used by Mr. W. Sidgreaves was achromatic, of 4 inches 

 aperture, kindly lent by the Royal Astronomical Society. It was equatorially 

 mounted upon a tripod stand ; slow motion in R.A. was effected by a handle 

 and Hook's joint. It was fitted with a solar diagonal reflecting prism. 



Time was recorded by Lieutenant T. G. FENN, of H.M.S. Volage, from the 

 Solar Chronometer Appleton 195. 



Nothing was seen of the Ingress. 



3 i 



