lentes

— After many vaine attempts to measure the circles made by coloured rays alone I at last thought of casting colours vpon a white paper, either by a speculum or immediatly by a Prisme which turned about its axis might make all yᵉ colours succed on yᵉ same pt of the paper; Or by casting integrated light on a paper wᶜʰ might bee varyed into all colours successively by stopping yᵉ rest. Then I laid the lentes so that they wanted 3 or 4 rings depth of touching.