520 Adams Recent Astronomical Discovery. | Oct., 
coercing it down to correspondence with her revolution.. We see 
her subjected, meanwhile, to other changes not less destructive. 
The bloom of life has long since passed from her face. Who shall 
say that our own beautiful earth will not one day resemble her? 
Our great terrestrial time-piece being slow, actually and also 
rateably, it follows that all astronomical phenomena referred to any 
fixed past epoch, apparently occur too soon, just as they would do 
if timed by a “slow” clock in an ordinary observatory. In each 
century, for instance, the sun’s apparent annual motion is accelerated 
by about 0'°4, the heliocentric motion of Venus by about 07, 
and that of Mercury by about 1'"7. After long intervals of time 
such changes must become appreciable. We have here, then, a 
test which future ages will be able to apply to the explanation 
offered by Delaunay. 
In whatever way the discrepancy detected by Prof. Adams may 
eventually be explamed, no doubt can exist of the importance of 
the discovery. It may rank worthily with the noblest labours 
of Clairant and Euler, Lagrange and Laplace, Airy, Hansen, and 
Leverrier. One achievement alone since Newton’s discovery of 
gravitation seems to claim a higher estimate,—in that achievement 
Adams shares equal honours with the illustrious Frenchman, 
Leverrier. 
