Batman vppon Bartholome his booke De proprietatibus rerum, newly corrected, enlarged and amended: with such additions as are requisite, vnto euery seuerall booke: taken foorth of the most approued authors, the like heretofore not translated in English. Profitable for all estates, as well for the benefite of the mind as the bodie. 1582.
Bartholomaeus, Anglicus, 13th cent., Trevisa, John, d. 1402., Batman, Stephen, d. 1584.

Of the light beame. cap. 43.

A Light beame is a bright streame of a bodye of lyght, by the which beame, lyght and shining doth his wor∣king, as Beda sayth. And some beame passeth straight forth, and commeth of the bodye of light, moouing by a straight line without blenching, and commeth to the middle point, and is called Perpen∣dicularis and Rectus: And some beame commeth of a bodie of lyght, and findeth a cleere body, and passeth not forth right, but sidelyng and blenching, and this blenching is called breaking of the beame. And such a light beame is called breaking of the Beame. And such a light beame is called Radius colleteralis, & Confractus. And the Sunne beame passeth straight foorth from the bodye of lyght, or blencheth aside, and méeteth with a bodye, that putteth and smiteth the light againwarde: and such a smi∣ting and putting is called bending of the beame: and such a Beame is called Radius reflexus, as the Authour of Per∣spectiue sayth. And so a Beame of light is moueable, and cleere, and bright, and rounde, and right of it selfe, and most conteined if it be of a straight Beame: and it happeneth sometime, that a light or bright beame is broken and shuft a∣side, or againeward, by the disposition of matter that it findeth and toucheth. Such a beame is closed in a hollowe clowde, and most worketh and maketh diuerse formes, coulours, shapes, and figures in the Clowde, or in the ayre, as it fareth in the coulours of the Raine-bowe, that is not else called, but entering of light beames into an hollowe clowde and wa∣tyre, as it is sayde libro Mecherorum: alwaye sodeinlye by moouing of beames that moue continuallye and sodeinlye, it happeneth that the ayre about is sette a fire: and namelye if the beames meete in the place of rebounding. For there the beames be gathered, and beat each other: and so they are cause why the ayre a∣bout is oft set a fire, as it fareth in Chri∣stall, and in Berrall. For if such a stone be set afore the Sunne, and put thereto, it shall set it on fire.