42 THE WORLD. 



moon, when her distance from the earth is known, than to deter- 

 mine the height of a church steeple when we know' how far it 

 is from the observer. We here represent the moon and. a part of 



B] 



its orbit, the earth being supposed to be at A. The distance A B 

 or A C, is 240,000 miles, and the angle B A C, which is observed 

 with a graduated circle, is about 30 minutes, or half a degree. 

 Proceeding as in the case of the Church, twice A C is 

 480,000 miles, and three times this is 1,444,000 miles which is the 

 circumference of a circle whose centre is the centre of the earth, 

 and whose radius, or half diameter, is the distance of the moon. 

 This circumference divided by 360, gives 4000 miles for the length 

 of one degree, and half this is 2000 miles the length of half a 

 degree, which is the diameter of the moon. The actual diameter 

 of the moon is 2140 miles, for the angle B A C is nearly 31 

 minutes, or a little over half a degree. 



In precisely the same manner the diameter of the sun is 

 ascertained to be 880,000 miles. Hence we learn, that if a spec- 

 tator at the sun, should look towards the earth, it would appear 

 only the one hundredth the diameter which the sun appears to us, 

 or not larger than a very small star. How absurd then is the idea 

 that the sun revolves around the earth. We now have a just 

 conception of Ihc solar system, and have learned to look upon the 

 sun as the central body, around which the planets revolve in order, 

 our earth being one of the smallest. Far beyond it, other magnifi- 

 cent orbs are moving silently in the depths of space, peopled with 

 myriads of intelligent beings. Very far beyond the boundary of 

 our own system, we believe there are others more beautiful, and 





