406 Life of the Rev. John llamsteed. [Dec. 



from him ; and Mr. Horrox's theory of the moon, to which 

 he had begun to fit some numbers; but perfected none that 

 I remember. 



About this time, Mr. Horrox's remains and observations 

 having been collected by Dr. Wallis, were in the press. [I 

 found his theory (of which a correct copy had fallen into 

 my hands) agree much better with my observations than 

 any other. Hereupon- 1 fitted numbers to it, which with 

 an explanation of it, were printed with his works.] Mr. 

 Collins advised me to print my discourse concerning the 

 Equation of natural days with them : which I consented to 

 do ; and sent it up to him for that purpose, translated into 

 Latin. 



[In March, 1671, setup a pole to raise my glasses, at 

 Derby.] It was October, 1671, before I could get my 

 tubes and micrometers in good order for observations. I 

 had no pendulum movement to measure time with : they 

 being not common in the country at that time. But, I took 

 the heights of the stars, for finding the true time of my 

 observations, by a wood quadrant about eighteen inches 

 radius, fixed to the side of my seven foot telescope ; which 

 I found performed well enough for my purpose. 



For, I had before resolved not to attempt anything that 

 lay out of my power, or for which I had not made such pro- 

 vision as might probably afford me success : and therefore 

 I resolved to confine myself to such observations as required 

 no very accurate knowledge of the times. Such were the 

 diameters of the luminaries ; small distances of the fixed 

 stars; the greatest elongations of Jupiter's satellites, &;c. ; 

 which might be of use to me in the further progress of my 

 astronomical studies. To such as these I confined myself 

 at first : and that Good Providence, that had designed greater 

 things to be afterwards done by me, gave me success beyond 

 my hopes or expectations. Having determined the diame- 

 ters of the sun, in his apogee and perigee, I saw the eccen- 

 tricity of the earth's orb was bisected. And observing the 

 moon's diameters in her appulse to the Pleiades, November 

 6th, 1671, when she was near the opposition of the sun, 

 and again February 23rd, 1672, when she was not far from 

 her quartile, I found that whereas the visible diameter ought, 

 according to the lunar theories of Bullialdus, Wing, and 



