34 CORRESPONDENCE OF RAY. 



you please, and reflecting upon some things that I had 

 formerly considered, I grew almost confident that it 

 might be done truly and geometrically by one that would 

 go to work with it the right way. I am not so foolish as 

 to think that I, who pretend not to be skilled so much as 

 in the elements of Conies, can add any thing unto what 

 they have done in their own way, in which they have 

 been so long conversant. Yet, in my first entrance, 

 there was one thing came into my mind, which all those 

 who have written upon this subject have either not taken 

 notice of, or neglected, which will go a great way in the 

 business, and that is this. 



Si dati sint duo coni Isosceles ejusdem altitudinis, 

 axem habentes communem, et secentm" hi coni a piano 

 axi parallelo, possibile est exhibere quadratum, quod 

 eandem habebit rationem ad spatium interceptum inter 

 lineam hyperbolicam, quae est in superficie majoris coni, 

 et lineam hyperbolicam qnee est in superficie minoris coni 

 ita secti, quam habeat linea hyperbolica minoris ad lineam 

 hyperbohcam majoris coni, addita linea hyperbolica mi- 

 noris coni. 



If you think this worth your consideration, I shall send 



you the demonstration at a more convenient time. 



I am, your affectionate friend and servant, 



Fra. Jessop. 

 BroomhaJl, Nov. 25, 1668. 



Mr. Wray to Mr. Lister. 

 Joannes Wray D. Martino Lister, suo S. D. 



QuoD partem ahquam lucubrationum tuarum mihi 

 inscribere destinaveris, plurimum me tibi debere agnosco, 

 proque tarn insigni tua voluntate et propenso in me animo 

 gratias quas possum maximas refero lul^ens merito. In- 

 terim tamen monendus es, ne dum affectui nimium in- 

 dulgeas miniis prudenter agas. Quin potius, dum 



