INDUCTIVE EPOCH OF NEWTON. 419 



Say ye who best can tell, ye happy few, 



Who saw him in the softest lights of life, 



All unwithheld, indulging to his friends 



The vast unborrowed treasures of his mind, 



Oh, speak the wondrous man ! how mild, how calm, 



How greatly humble, how divinely good, 



How firm established on eternal truth ! 



Fervent in doing well, with every nerve 



Still pressing on, forgetful of the past, 



And panting for perfection ; far above 



Those little cares and visionary joys 



That so perplex the fond impassioned heart 



Of ever-cheated, ever-trusting man. 



[2d Ed.] [In the first edition of the Principia, published in 1687, 

 Newton showed that the nature of all the then known inequalities of 

 the moon, and in some cases, their quantities, might be deduced from 

 the principles which he laid down : but the determination of the amount 

 and law of most of the inequalities was deferred to a more favorable 

 opportunity, when he might be furnished with better astronomical ob- 

 servations. Such observations as he needed for this purpose had been 

 made by Flamsteed, and for these he applied, representing how much 

 value their use would add to the observations. "If," he says, in 1694, 

 " you publish them without such a theory to recommend them, they will 

 only be thrown into the heap of the observations of former astronomers, 

 till somebody shall arise that by perfecting the theory of the moon shall 

 discover your observations to be exacter than the rest ; but when that 

 shall be, God knows : I fear, not in your lifetime, if I should die before 

 it is done. For I find this theory so very intricate, and the theory of 

 gravity so necessary to it, that I am satisfied it will never be perfected 

 but by somebody who understands the theory of gravity as well, or 

 better + han I do." He obtained from Flamsteed the lunar observations 

 for which he applied, and by using these he framed the Theory of the 

 Moon which is given as his in David Gregory's Astronomies Elemental 

 He also obtained from Flamsteed the diameters of the planets as ob- 

 served at various times, and the greatest elongation of Jupiter's Satel- 

 lites, both of which, Flamsteed says, he made use of in his Principia. 



Newton, in his letters to Flamsteed in 1694 and 5, acknowledges 

 this service. 28 



27 In the Preface to a Treatise on Dynamics, Part i., published in 1836, 1 have 

 endeavored to show that Newton's modes of determining several of the lunar in- 

 equalities admitted of an accuracy not very inferior to the modern analytical methods. 



,8 The quarrel on the subject of the publication of Flamsteed's Observations took 



