78 THE NEBULA IN ANDROMEDA. 



be reconciled with its appearance at the present day, it may rea- 

 sonably be concluded that the views of Le Gentil, with regard 

 to its variability, are far from being supported by an amount of 

 evidence adequate to such a conclusion. Messier, in 1771. 

 remarks, that for fifteen years he had noticed no change in the 

 nebula ; it always appeared to him bright at the centre, the light 

 fading away insensibly towards both extremities, its figure re- 

 sembling that of two cones with their bases opposed. In the 

 Philosophical Transactions for 1785, it is thus described by Sir 

 William Herschel. 



" It is undoubtedly the nearest of all the great nebulae ; its extent is about 

 a degree and one half in length, and, in even one of the narrowest places, not 

 less than sixteen minutes in breadth. The brightest part of it approaches to 

 the resolvable nebulosity, and begins to show a faint red color ; which, from 

 many observations on the color and magnitude of nebulae, I believe to be an 

 indication that its distance in its colored parts does not exceed two thousand 

 times the distance of Sirius. 



" There is a very considerable, broad, pretty faint, small nebula near it ; 

 my sister discovered it, August 27th, 1783, with a Newtonian two-feet sweep- 

 er. It shows the same faint color with the great one, and is, no doubt, in the 

 neighbourhood of it. It is not the 32d of the Connaissance des Temps ; 

 which is a pretty large, round nebula, much condensed in the middle, and 

 south-following the great one ; but this is about two thirds of a degree north- 

 preceding it, in a line parallel to and y Andromedae." 



In the same memoir from which the above extract is taken 

 occurs the following passage. 



" But it is nevertheless very evident that the united lustre of millions of 

 stars, such as I suppose the nebula in Andromeda to be, will reach our sight 

 in the shape of a very small, faint nebulosity ; since the nebula of which I 

 speak may easily be seen in a fine evening." 



