A primary astronomy .. . erihelion and Aphelion points lie? Her Perihelion is in Gemini, and her Aphelion inSagittarius. 353. When is the Earth nearest to the Sun, or at Perihelion ?About the first of January. 354. When is she at her greatest distance 1Six months afterward, or July 3. 355. How is it, then, that it is cold in January, when the Sunis nearest; and warm in July, when heis most distant! It is because the NorthernHemisphere inclines toward theSun in July, and from him inJanuary. [The comparative amount of light received inthe Northern Hemisphere in July and January,may be illustrate
A primary astronomy .. . erihelion and Aphelion points lie? Her Perihelion is in Gemini, and her Aphelion inSagittarius. 353. When is the Earth nearest to the Sun, or at Perihelion ?About the first of January. 354. When is she at her greatest distance 1Six months afterward, or July 3. 355. How is it, then, that it is cold in January, when the Sunis nearest; and warm in July, when heis most distant! It is because the NorthernHemisphere inclines toward theSun in July, and from him inJanuary. [The comparative amount of light received inthe Northern Hemisphere in July and January,may be illustrated by the accompanying figure, in which the rays of light at different seasons are represented to the eye. Tn Januarythey are seen to strike the Northern Hemisphere obliquely; and consequently thesame amount of light is spread over a much greater surface. In July the rays fallalmost perpendicularly upon us, and are much more intense. Hence the variations oftemperature which constitute the Seasons.] SUMMER AND WINTER 356. What is the difference of the Earths distance in July andJanuary? About three millions of miles. 357. Does not this in reality affect the general temperature ofthe Earth 7 It undoubtedly does; but the variation of 3,000,000miles is so slight when compared with the whole dis-tance of the Sun, that the change of temperature pro-duced thereby is imperceptible. PHIMARY ASTRONOMY. 79 [The natural effect of this variation would be, so far as it had any influence, tomodify the cold and heat in the Northern Hemisphere, and to augment both in theSouthern. For instance, our nearness to the Sun in January would slightly soften ourWinter, while, at the same time, it slightly increased the heat of the Summer south ofthe equator. So, also, our increased distance in July would diminish the heat of ourSummer, and at the same time enhance the cold of the corresponding Winter in theSouthern Hemisphere.] 35 §. What are the Equinoctial Points in the Earths orbit ? They are
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