and vice versa. Now, the earth has always one side dark and the other side light ' T 

 and that both sides may enjoy the cheering rays of the sun, the earth is constantly 

 revolving upon its axis, thus bringing every part of its surface, once in every 

 twenty-four hours, under the influence of the meridian sunlight, and once into the 

 position immediately opposite. Accordingly, while it is mid- day in England, it is 

 mid-night on the opposite side of the globe, or in New Zealand. 



THE SEASONS 



The grand cause of the seasons is the inclination of the axis of the earth to the 

 plane of its orbit, during the revolution of the globe round the sun. This inclina- 

 tion is to the extent of 23^ degrees, and is always preserved ; the north pole of the 

 earth being constantly directed to the same point in the heavens. In consequence 

 of this, the north and south poles of the earth are alternately presented to the in- 

 fluence of the sun's light and heat ; so that, when it is summer in the northern 

 hemisphere, it is v* inter in the southern, and vice versa. We will briefly follow the 

 earth's progress in its orbit during the different seasons. 



On the 20th March the sun is vertical on the equator, his rays fall equally on 

 the northern and southern hemispheres, and the days and nights are equal in 

 length all over the world. This is the SPRING EQUINOX. The earth proceeds in 

 its orbit, gradually the north pole comes more under the influence of the sun's ray&, 

 which fall more and more perpendicularly ; and the length of the days exceeds 

 that of the nights, in proportion to the distance from the equator, until the 21=t 

 June, when the sun becomes vertical at the tropic of Cancer, and we reach the 

 SUMMER SOLSTICE. After this, the earth proceeding in its course, the north pole 

 gradually recedes from the sun, the days shorten, the sun's rays become more 

 oblique, and on the 23rd September the sun is again vertical at the equator, and 

 we arrive at the AUTUMNAL EQ.UINOX. The earth speeds onward, the days be- 

 come shorter than the nights, the sun's rays fall more and more obliquely on the 

 northern hemisphere until the 21st December, when we reach the WINTER SOL- 

 STICE. The north pole is now furthest inverted from the sun, which has become 

 vertical at the tropic of Capricorn. The earth hastens on its way ; our days be- 

 gin to lengthen ; and the sun's rays gradually increase in power. On the 20th 

 March the sun is again vertical on the equator, and we rejoice in the return of 

 spring. 



THE MOON AND ITS PHASES. 



Our satellite the Moon is a globe 2,160 miles in diameter, and revolves round the 

 earth at a distance of 240,000 miles, in 27 days 7 hours 43 minutes and 11 

 seconds. 



When viewed through a telescope her surface appears very bright and extremely 

 rugged, presenting numerous mountains and deep excavations or hollows. There 

 are no traces of water nor of an atmosphere. 



The Phases of the Moon arise from the different positions which it assumes in rela- 

 tion to the sun and the earth during its revolution round the latter. When the moon 

 is between the sun and the earth, its dark side is presented to us, and it is conse- 

 quently invisible ; in this position it is called the NEW MOON. Four days after the 

 time of new moon it has receded 45 degrees from the sun, and now a portion of its 

 illuminated surface is seen in the form of a crescent. After eight days it has de- 

 parted 90 degrees from the sun, and shows a bright semi-circular disk ; the moon 

 is now said to be in its FIRST QUARTER. Gradually showing more of i'S illuminated 

 surface, it becomes gibbous ; and about fifteen days after the time of new moon, it 

 stands directly opposite the sun, presenting a complete circular disk ; this is the 

 FULL MOON, rising when the sun sets, and shining through the whole night. Pro- 

 ceeding in its course, its illuminated surface gradually decreases ; approaching the 

 BUII it becomes a second time gibbous ; a half- moon at its LAST QUARTER ; assumes 

 a crescent form ; and completing its orbit, disappears ; becoming a ntw moon 

 again as at first. 



ECLIPSES. 



When an heavenly body is darkened by the shadow of another heavenly body 

 falling upon it, that heavenly body is said to be eclipsed. 



ECLIPSE OF THE MOON. An eclipse of the moon is caused by the earth so com- 

 ing between the sun and moon as to prevent the sun's rays falling upon the latter; 

 this can only happen at the time of full moon. If the moon's orbit were parallel to 

 the plane of the ecliptic, we should have an eclipse of the moon every month, at the 

 lime of full moon, and one of the sun at the time of every new moon ; but this does 



