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onely very delightful, but to such as know not the contrivance, very wonderful; so that Spectators, not well versed in Opticks, that should see the various Apparitions and Disappearances, the Motions, Changes, and Actions, that may this way be represented, would readily believe them to be super-natural and miraculous, and would as easily be affected with all those passions of Love, Fear, Reverence, Honour, and Astonishment, that are the natural consequences of such belief. And had the Heathen Priests of old been acquainted with it, their Oracles and Temples would have been much more famous for the Miracles of their Imaginary Deities. For by such an Art as this, what could they not have represented in their Temples? Apparitions of Angels, or Devils, Inscriptions and Oracles on Walls; the Prospect of Countryes, Cities, Houses, Navies, Armies; the Actions and Motions of Men, Beasts, Birds, &c. the vanishing of them in a cloud, and their appearing no more after the cloud is vanisht: And indeed almost any thing, that may be seen, may by this contrivance be very vividly and distinctly represented, in such a manner, that, unless to very curious and sagacious persons, the means how such Apparitions are made, shall not be discoverable. The way in short is this;
Opposite to the place or wall, where the Apparition is to be, let a Hole be made of about a foot in diameter, or bigger; if there be a high Window, that hath a Casement in it, 'twill be so much the better. Without this hole, or Casement open'd at a convenient distance, (that it may not be perceived by the Company in the room) place the Picture or Object, which you will represent, inverted, and by means of Looking- glasses placed behind, if the picture be transparent, reflect the rayes of the Sun so, as that they may pass through it towards the place, where it is to be represented; and to the end that no rayes may pass besides it, let the Picture be encompass'd on every side with a board or cloath. If the Object be a Statue, or some living Creature, then it must be very much enlighn'd by casting the Sunbeams on it by Refraction, Reflexion, or both. Between this Object, and the Place where 'tis to be represented, there is to be placed a broad Convex-glass, ground of such a convexity, as that it may represent the Object distinct on the said place; which
