Opticks: or, a treatise of the reflexions, refractions, inflexions and colours of light / Also two treatises of the species and magnitude of curvilinear figures.

  • Newton, Isaac, 1642-1727.
Date:
1704
Catalogue details

Licence: Public Domain Mark

Credit: Opticks: or, a treatise of the reflexions, refractions, inflexions and colours of light / Also two treatises of the species and magnitude of curvilinear figures. Source: Wellcome Collection.

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    fufFers a greater Refraftion. If the edge of the refrading Angle be turned downward, the Image of the Paper will be refraded downward fuppofe to and the blew half will be refradled lower to ^ y than the red half is to 9 Exper, 2. About the aforefaid Paper, whofe two halfs were painted over with red and blew, and which was ftiff like thin Paftboard, I lapped feveral times a (lender thred of very black Silk, in fuch manner that the feveral parts of the thred might appear upon the Colours like fo many black Lines drawn over them, or like long and flender dark Shadows call upon them. I might have drawn black Lines with a Pen, but the threds were fmaller and better defined. This Paper thus coloured and lined I fet againft a Wall perpendicularly to the Horizon, fo that one of the Colours might Hand to the right hand and the other to the left. Clofe before the Paper at the confine of the Co¬ lours below I placed a Candle to illuminate the Paper ftrongly : For the Experiment was tried in the Night* The flame of the Candle reached up to the lower edge of the Paper, or a very little higher. Then at the diftance of Six Feet and one or two Inches from the Paper upon the Floor I ere6led a glafs Lens four Inches and a quarter broad, which might colledl the Rays coming from the feveral Points of the Paper, and make them converge to¬ wards fo many other Points at the fame diftance of fix Feet and one or two Inches on the other fide of the Lens,, and fo form the Image of the coloured Paper upon a white Paper placed there 5 after the fame manner that a Lens at a hole in a Window cafts the Images of Objefts abroad upon a Sheet of white Paper in a dark Room. The afore¬ faid white Paper, eredled perpendicular to the Horizon and to the Rays which fell upon it from the Lens, I moved fometimes towards the Lens, fometimes from it, to find the