14 quotes
Proposition 9. The diameter of the sun is greater than 18 times, but less than 20 times, the diameter of the moon.
On the Sizes and Distances of the Sun and the Moon (-250)
Proposition 6. The moon moves (in an orbit) lower than (that of) the sun, and, when it is halved, is distant less than a quadrant from the sun.
On the Sizes and Distances of the Sun and the Moon (-250)
Proposition 4. The circle which divides the dark and the bright portions in the moon is not perceptibly different from a great circle in the moon.
On the Sizes and Distances of the Sun and the Moon (-250)
Proposition 8. When the sun is totally eclipsed, the sun and the moon are then comprehended by one and the same cone which has its vertex at our eye.
On the Sizes and Distances of the Sun and the Moon (-250)
Proposition 2. If a sphere be illuminated by a sphere greater than itself, the illuminated portion of the former sphere will be greater than a hemisphere.
On the Sizes and Distances of the Sun and the Moon (-250)
Proposition 7. The distance of the sun from the earth is greater than eighteen times, but less than twenty times, the distance of the moon from the earth.
On the Sizes and Distances of the Sun and the Moon (-250)
Proposition 15. The diameter of the sun has, to the diameter of the earth a ratio greater than [6.3] that which 19 has to 3, but less than [7.2] that which 43 has to 6.
On the Sizes and Distances of the Sun and the Moon (-250)
Proposition 3. The circle in the moon which divides the dark and the bright portions is least when the cone comprehending both the sun and the moon has its vertex at our eye.
On the Sizes and Distances of the Sun and the Moon (-250)
Proposition 10. The sun has to the moon a [volume] ratio greater than that which 5832 has to 1, but less than that which 8000 has to 1.
On the Sizes and Distances of the Sun and the Moon (-250)
Proposition 16. The sun has to the earth a [volume] ratio greater than [254] that which 6859 has to 27, but less than [368] that which 79507 has to 216.
On the Sizes and Distances of the Sun and the Moon (-250)
Proposition 11. The diameter of the moon is less than 2/45ths [0.04], but greater than 1/30th [0.03] of the distance of the centre of the moon from our eye.
On the Sizes and Distances of the Sun and the Moon (-250)
Proposition 18. The earth is to the moon in a [volume] ratio greater than [15.8] that which 1259712 has to 79507, but less than [31.5] that which 216000 has to 6859.
On the Sizes and Distances of the Sun and the Moon (-250)
Proposition 12. The diameter of the circle which divides the dark and the bright portions in the moon is less than the diameter of the moon, but has to it a ratio greater than [0.99] that which 89 has to 90.
On the Sizes and Distances of the Sun and the Moon (-250)
Proposition 17. The diameter of the earth is to the diameter of the moon in a ratio greater than [2.51] that which 108 has to 43, but less than [3.16] that which 60 has to 19.
On the Sizes and Distances of the Sun and the Moon (-250)