Diagram, by John Collins Diagram of the problem John Collins wished Henry Oldenburg to pose to Renatus Franciscus Slusius: whether he had a construction 'for salving of Solid problemes, wherein the Axes either of a Parabola or Hyperbola, and the longer Axis of an Ellipses or any two of these figures may meet without the concave figure'. Shows two curves (hyperbola and parabola) intersecting with an oval (ellipsis) and lines drawn through these curves which come together to form a point. Above, there is writing explaining the diagram. Collins wrote the letter in English, which Oldenburg then translated into Latin. The English version of the letter is the one depicted here, and copies of the Latin version can be found in the Letter Book [LBO/3/178] and its copy [LBC/3/217]. Subject: Mathematics, Astronomy c.12 September 1669