A general view of the sciences and arts, Volume 2

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Page 282 - Pouring forth tears at such a lavish rate, That were the world on fire, they might have drown'd The wrath of Heaven, and quench'd the mighty ruin.
Page 24 - It' a man place himself directly before a large concave mirror, but farther from it than its centre of concavity, he will see an inverted image of himself in the air, between him and the mirror, of a less size than himself. And if he hold...
Page 14 - ... the angle of reflection is always equal to the angle of incidence, the image for any point can be seen only in the reflected ray prolonged.
Page 24 - ... than himself, and if he hold out his hand towards the mirror, the hand of the image will come out towards his hand, and coincide with it...
Page 15 - In a very dark Chamber at a round hole about one third part of an Inch broad made in the Shut of a Window I placed a Glass Prism, whereby the beam of the Sun's Light which came in at that hole might be refracted upwards toward the opposite Wall of the Chamber, and there form a coloured Image of the Sun.
Page 254 - II. A Dilemma is an argument which divides the whole into all its parts or members by a disjunctive proposition, and then infers something concerning each part which is finally inferred concerning the whole.
Page 4 - ... fuppofing a line drawn perpendicularly to the furface of the medium, through the point where the ray enters, and extended both ways, the ray, in paffing through the...
Page 15 - ... passing through the middle of the prism from one end of it to the other end parallel to the edge of the refracting angle) was in this and the following experiments perpendicular to the incident rays. About this axis I turned the prism slowly, and saw the refracted light on the wall or coloured image of the sun first to descend, and then to ascend. Between the descent and ascent when the image seemed stationary, I stopped the prism, and fixed it in that posture, that it should be moved no more.
Page 25 - If he reach his hand farther, the hand of the image will pass by his hand, and come between it and his body ; and if he move his hand towards either side, the hand of the image will move towards the other ; so that, whatever way the object moves, the image will move the contrary way. A bystander will see nothing of the image, because none of the reflected rays that form it enter his eyes.
Page 57 - The needle with the card turns on an upright pin fixed in the centre of the box. In the centre of the needle is fixed a brass conical socket or cap, whereby the card hanging on the pin turns freely round the centre. The top of the box is covered with a glass that the card's motion may not be disturbed by the wind.

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