112 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. 



The motions are carried on by a train of wheel- work con- 

 cealed in the brass box, under the ecliptic. 



In the centre of the system is the sun, placed in the 

 heavens by that Almighty Power, who said, "Let there be 

 light, and there was light," to be the fountain of light and 

 heat to all the planets revolving round him. 



The nearest planet to the sun is Mercury ; observe the 

 part of the ecliptic he is at, and also the place where the 

 earth is situate. I now turn the handle, Mercury is arrived 

 at the place from whence he set out, and our earth has gone 

 over 88 days of the ecliptic ; the velocity we here give the 

 planet is inconsiderable, but in his course in the heavens he 

 is supposed to move with a velocity equal to 100,000 miles 

 in an hour. 



Venus is the next planet in the system ; in the heavens 

 she is distinguished by the superiority of her lustre, appear- 

 ing to us the brightest and largest of all the planets. By 

 observing her course through the ecliptic, and comparing it 

 with the days passed over by the earth in the same time, 

 you will find, in the instrument, Venus revolving round the 

 sun in 225 days ; in the heavens she moves at the rate of 

 80,955 miles in an hour. 



The third planet in the solar system is the Earth ; dimi- 

 nutive as it appears before you in this instrument, its real 

 diameter is near 8000 miles ; it revolves round the sun in 

 the space of 365 days, into which number the brazen eclip- 

 tic is divided ; this revolution constitutes our year, while its 

 revolution round its axis forms day and night. 



The little ball, close and annexed to the earth, represents 

 the Moon. 



The planet Mars is the next in order, being the first 

 above the earth's orbit ; he revolves round the sun in about 

 686 days ; so that our earth, as you will observe by the 

 instrument, goes nearly twice round, while he is performing 

 his revolution; he is supposed to move at the rate of 55,783 

 miles in an hour. To this planet our earth and moon will 

 appear like two moons, sometimes half or three quarters 

 illuminated, but never full. 



Jupiter, the largest of all the planets, is next beyond 

 Mars ; and our earth must have gone nearly twelve times 

 round the ecliptic for one revolution of Jupiter ; yet so far 

 is its path removed from the sun, that to go round it in 

 this space of time, it moves at the rate of 30,193 miles an 



