VOL. X.] PHILOSOPHICAL TRANSACTIONS. 221 



signed nothing but to assert to the dead an invention, which he esteemed the 

 best he ever made, and which is the chief of his monuments : this had I neglected, 

 I had been unjust to the dead, whose papers passed through my hands to the 

 public; nor have, I hope, been at all injurious to Mr. Street in it. 



For my assertion concerning his figure of the lunar system was, that the 

 contrivance of it, for the motion of longitude, was no other than what was taken 

 from Mr. Horrox's theory, and my explication ; whereby I conceive no man 

 would understand me of his numbers. 



Perhaps he will say, he has transferred the libratory circle from the orbis 

 magnus to the transverse diameter of the ellipsis. But this is not material, 

 since the effect is still the same ; and supposing the same diameter of the libra- 

 tory circle, the same equations will be found, to a second ; so that hereby he 

 only has gained a pretext to call the system his own, but he has rendered the 

 case of the libration less intelligible. 



He adds, that " he has increased the quantity of the greatest libration 22 min.'* 

 So that the semi-diameter of the little circle, that shows the variation, may sub- 

 tend the greater equation of the apogee, the mean eccentricity being radius. 

 This indeed is an ingenious conceit; yet it amounts to no more than an altera- 

 tion ; which, whether the heavens will admit of, we may justly question. I find 

 by Mr. Horrox's papers, that he used at first 12° precisely, but on farther expe- 

 rience diminished it to 11° 48'. 



But the main part of his defence is, that his numbers are not the same with 

 those published with the Horroxian theory, and therefore the system is not the 

 same. I argue not how illogical the inference is ; but how little ingenuous, you 

 may judge, in that he has published only the aforementioned coarse ones, so 

 that for the eccentricity and variation we must believe him gratis. Nor is it 

 pertinent what he says concerning the working of proportions in triangles me- 

 chanically. If he knew how to do it before me, no less did others much longer 

 before him ; nor am I at all beholden to him for this skill : but if he prefers 

 calculations before it, to what purpose is this print of the lunar plate, or his con- 

 tention about it. 



A Total Eclipse of the Moon, observed in London, June 26, 1675, by Mr, John 

 Flamsteed, Astronomer Royal. N°ll6, p. 371. 



Beginning of the penumbra 13h. 46m. 40s. 



The total immersion 14 56 55 



The same observed at Paris by M. Bulliald. 



Beginning of the true umbra 13 55 O 



The total immersion 15 6 O 



