|Description||Rix reports that the letter of 1 July 1672 which accompanied the 'Problema Alhazeni' is in its place in the Royal Society's collection, but he suspects that Dr Bierans de Haan must have had a copy of it which was before him when he wrote for a copy of 'Problema'. He points out that Bosscha dates the letter as 1 July 1676, and suggests that this could be why he cannot find it. If Bosscha wishes for the letter to be copied, Rix can get a copyist to transcribe it for him.|
The writing, of which Bosscha has sent a tracing, is noted by Rix as definitely not be that of Oldenburgh, but rather an amanuensis employed by the Society at the time to copy communication into their Letter Books and Journal Books. The 'Explicatio Figurae' is indeed in their book of copied letters in the same hand.