Whosoever desyres to see the Sun eclipsed without hurting their eyes: Let them beholde the shadow therof in a vessel, wherin oyle is put: Where, they may beholde and see it without daunger. For a fatty humor is not easely troubled. And what shapes or fourmes it doth receyve: It representeth the same truely.
Thomas Lupton, One Thousand Notable Things (1579)
Now I have determined to shew how the Suns Eclipse may be seen. When the Sun is Eclipsed, shut your Chamber-windows, and put a paper before a hole, and you shall see the Sun: let it fall upon the paper opposite from a Concave-glass, and make a circle of the same magnitude: do so at the beginning, middle, and end of it. Thus may you without any hurt to your eyes, observe the points of the diameter of the Suns Eclipse.
Giambattista della Porta, Natural Magick (1658)
Forgot to buy NASA-approved solar glasses? These methods are approved by the Past.