ACCOMPANYING THE AURORA BOREALIS. 627 
affords more ample scope for a base line than the 
distance between Cambridge and Kimbolton, and 
therefore I think the luminous arch of November 
3rd, 1834, was probably six hundred or eight 
hundred miles from the earth; being far beyond 
the height as calculated by Mr. Cavendish, of 
that which was seen at Cambridge, Kimbolton, 
&e. 
