( ?i8 ) 1 
lar Probleme propofed in this Letter is a fpecial Cafe, | 
not of the general Probleme firft propofed, as it ought I 
to have been, but of this new double Probleme. And I 
the firft part of this double Probleme (viz. by any I 
given property of a Series of Curves to find the Curves) I 
is a Probleme harder than the former, and of which a I 
general Solution is not yet given. Mr. Leibnitz in a / 
Letter to Mr. John Bernoulli, dated i6 December, 1694. f 
and publiflied in the A^a Eruditorum for October 1698. ^ 
/>. 471, letdown his Solution of the Probleme, when j 
the given Series of Curves is defined by a finite Equa- | 
tion, exprefting the relation between the Abfcifs and 7 
Ordinate. The fame Solution holds when the Equa- 
tion is a converging Series, or when the property of the 
Curve to be cut can be reduced to fuch an Equation, 
by the And)(is per Series numero terminorum infinitas. 
But Mr. Leibnitz was for folving the Probleme without, 
converging Series. 
IV. ^ars 
