( ' 4 ! ) 
V. A Letter from Mr. Colin Mac Laurin, 
Math. Prof. Edinburg. F. R. S. to Mr. John 
Machin, Aftr. Prof. Grefh. & Seer. R. S. 
-concerning 'the Defcription of Curve Lines. 
Communicated to the (Royal Society on Decem- 
ber 2 1 3 1732. 
I Am informed that fome Papers have been pre- 
fented to the Royal Society of late, concerning 
the Defcription of Curves, in a manner that has a 
near affinity to that which I communicated to them 
of old, and have carried farther fince ; and that it 
would not be unfeafonable, nor unacceptable, if I 
ffiould fend an Account of what I have done further 
on that Subjedt fince the Year 1719. The Author 
of thofe Papers taught Mathematicks here privately 
for fome Years, and fometime ago (viz. in 1727.) 
mentioned to me fome Theorems he had on that 
Subjedt ; which, at the lame time, I Ihewed him in 
my Papers. Some time before that, he Ihewed me 
a Theorem which coincided with one of thofe in 
my Book, tho’ he feemed not to have obferved that 
Coincidence ; and indeed Methods of that kind, 
are often found coincident that do not appear fuch 
at firft fight. I am unwilling to be the Occafion 
of difeouraging any thing that is truly ingenious, 
and renounce any Pretenfions of appropriating 
Subjects to my felf:, but, on the contrary, wilh 
Juftice may be done to every Perfon, or to any 
Performance in Proportion to it Merit ; yet I find 
T it 
