We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.
Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.
26 parts of the Earth on which the point of the conical shadow falls. Besides the dark shadow called the umbra , there is a lighter one called the penumbra, which diverges, becoming lighter the farther it spreads from the umbra. In those parts where it falls, the Sun is partially eclipsed ; more or less of it being hidden, in proportion as the observer is nearer to or farther from the umbra, where it is totally obscured. The shadow caused by the Earth is much larger, and is about 840,000 miles in length. When the Moon enters this shadow, she suffers a deprivation of light; more or less of her disk being eclipsed according to the degree in which she enters the shadow. An eclipse of the Sun can only happen at new moon, when she is said to be in conjunction , the Moon being then between the Sun and the Earth ; and an eclipse of the Moon at full moon or when in opposition , as the Earth is then between the Sun and Moon. DIAGRAM XXIII. Explains the cause why an eclipse of the Sun does not happen every new moon, and an eclipse of the Moon at every full. The small blue circles represent the orbit of the Moon on the plane of the ecliptic ; in which case there is evidently nothing to prevent an eclipse always happening at those times. But the Moon’s orbit being inclined to that of the Earth, as represented by the light circles, she generally passes either above or below the Sun, and no eclipse takes place ; and it is only when the situation of one of the nodes nearly corresponds with the Moon’s conjunction, that an eclipse of the Sun can take place; or, when it corresponds with the opposition or full moon, that an eclipse of the Moon can take place. The nodes of the Moon’s orbit do not remain stationary, but revolve in a retrograde direction once in 18 years and 10 days; and as that period corresponds very nearly with 223 revolutions of the Moon, she