387194r
[Commentary:
This page is part of Harriot's
experiments on refractive colours. Having found the secondary, colour-producing cardinal ray for the glass prism, Harriot turns to the water-filled prism. He first explores the possibility that the ratio between the primary and secondary cardinals for the water prism is the same as the ratio between the primary and secondary cardinals in the glass prism. He finds that this does not in fact accord with observation. Thus he will follow the same procedure as in the glass prism to find the secondary cardinal. ]
A. De coloribus per angulum
[Translation: On colours through a water prism. ]
[Translation: On colours through a water prism. ]
Ponamus primo: secundarium cardinalem aquae ad primarium
esse ut secundarius vitri ad
[Translation: Let us first assume: that the [ ratio of the] secondary cardinal of water to the primary is the same as the secondary primary of water to its primary. ]
illam rationem non probant
[Translation: The observations do not support that ratio. ]
esse ut secundarius vitri ad
[Translation: Let us first assume: that the [ ratio of the] secondary cardinal of water to the primary is the same as the secondary primary of water to its primary. ]
illam rationem non probant
[Translation: The observations do not support that ratio. ]
Ponamus 2o cardinalem secundarium 48° 20â².
Sed precedit [sic] operatio per primarium ut in (D) vitri.
[Translation: Let us assume that the secondary cardinal is 48° 20â². But the operation proceeds by means of the primary cardinal, as on page D of the glass [prism]. ]
Sed precedit [sic] operatio per primarium ut in (D) vitri.
[Translation: Let us assume that the secondary cardinal is 48° 20â². But the operation proceeds by means of the primary cardinal, as on page D of the glass [prism]. ]