LETTERS ON SCIENTIFIC SUBJECTS. 105 



mean time, our mathematicall mechanicians doe not want ex- 

 ceptions against the extraordinarines of the contrivance. 



******** 

 Your Lordship's very humble and faithful servant, 



H. O. 



For the Right Honourable the Lord Brereton 

 at Brereton in Cheshire. Stonebagg. 



P.S. Mr. Hook presents his humble service to your Lord- 

 ship, and begs the favor to send him some account of the 

 causeway found so deep under ground, and of what shels are 

 found in stones, or ligna fossilia &c. Whereby you will 

 much oblige him. 



MICHAEL DARY TO JOHN COLLINS. 



[MS. Birch, 4425, fol. 54, r. Orig.] 



The equation is this : 



+ V 4 + 8 V 3 - 24 y 9 4- 104 y 676 = 



Mr. Collins, I have beene lately trying to break biqua- 

 dratique equations into two quadratique ones, and I have 

 effected my purpose in a great many, some by the aliquote 

 parts, and some by the cubicall mant, but this soure crabb I 

 cannot deale with by no method, &c. 



Your servant, 



MICH : DARY. 

 Tower, the 8th Febr: 1674-5. 



NOTE ON THE SOLVING EQUATIONS, BY JOHN 



PELL. 



[MS. Birch, Brit. Mus. 4432, fol. 26, Orig.] 



May 20, 1675. 



Mr. Dary only solved cubick equations by ayd of a qua- 

 dratick equation in a particular case, not knowing the use of 

 both the rootes of his quadratick equation; but Collins 

 knowing how to take away two tearmes in any equation 

 hath a different generall method of solving these and higher 



