18 
MR. TALBOT’S RESEARCHES IN THE INTEGRAL CALCULUS. 
their signs) the sum of two of them shall be equal to the third (though not super- 
posable in any part). I believe that it has been hitherto held that this equality is 
impossible in the ellipse and hyperbola, without the addition of some algebraic quan- 
tity. I should have wished therefore to have added some numerical illustration of 
such a result, but the length of the calculation has hitherto prevented me from 
doing so. 
