THE COMING TRANSIT OF VENUS. 15 



THE COMING TRANSIT OF VENUS, AND BRITISH 

 PREPARATIONS FOR OBSERVING IT. 



BY far the most important of all the phenomena which 

 astronomers are now expecting is the transit of Venus, 

 which will take place on December 8, 1874. Even 

 the eclipses of the last few years, though they have 

 attracted so much attention, and have been observed so 

 carefully,have in reality been regarded as altogether less 

 important than the next transit of Venus. Total eclipses 

 are almost every-year phenomena, but transits of Venus 

 occur only at average intervals of more than half a 

 century. The last took place in 1769, and after the 

 transit of 1882 none will occur till 2004. Apart from 

 this circumstance, a transit of Venus is of extreme 

 importance in the science of astronomy. It admittedly 

 affords the most satisfactory means of determining the 

 distance of the sun in other words, the dimensions of 

 the solar system itself. And such determination of the 

 scale on which our system is constructed affords the 

 only means we possess of measuring the vast spaces 

 which separate us from the fixed stars. So that the 

 observations which are to be made in December, 1874, 

 and renewed (but under somewhat different conditions) 

 in December, 1882, bear directly on the fundamental 

 problem of astronomy, so far as astronomy relates to 



