no ECLIPSES OP THE SUN. 



moon be in one of her nodes, she will, in most cases, cover 

 the whole disk of the sun and produce a total eclipse ; if she 

 be any where within about sixteen degrees of anode, b, par- 

 tial eclipse will be produced. When a bright luminous 

 ring appears round the dark body of the moon during an 

 eclipse of the sun, it is called an annular eclipse. This 

 kind of eclipse is occasioned by the moon being at her 

 greatest distance from the earth at the time of an eclipse ; 

 in which situation, the vertex or point of the con,e of the 

 moon's shadow does not reach the surface of the earth. A 

 total eclipse of the sun is a very curious and uncommon 

 spectacle; and total darkness cannot last more than three or 

 four minutes. Of one tliat was observed in Portugal more 

 than one hundred and fifty years ago, it is said that the 

 darkness was greater than that of night ; — that some of 

 the largest stars made their appearance ; — and that birds 

 were so terrified that they fell to the ground. A very re- 

 markable total eclipse took place in New England June 16, 

 1806. The day was clear ; several stars were visible; the 

 birds were greatly agitated ; and a gloom spread over the 

 landscape. The first gleam of light, contrasted with the 

 previous darkness, seemed like the usual meridian day. 



Questions. — 1, What is an eclipse of the moon ? 2. Describe 

 the earth's shadow. 3 When does an eclipse of the moon happen'' 

 4. Why is she not eclipsed at every full moon ? 5. How near a node 

 must she be in order to be eclipsed ? 6. How long may an eclipse of 

 the moon last .'' 7. From the knowledge of what circumstances are 

 hmar eclipses calculated ? 8. Over what part of the earth are they 

 visible.' 9. What is the cause of an eclipse of the sun.'' ]0. When 

 does an eclipse of the sun happen ? 11. Why can it not happen at 

 other times ? 12. W^hen will the moon produce a total eclipse of the 

 sun .'' 13. Partial .'' 14. When is an eclipse of the sun called annu- 

 lar .'' — why .'' 15. What occasions this kind of eclipses ? 16. How 

 long may a total eclipse of the sun last.'' [Note. The diameters of 

 the sun and moon are supposed to be divided into 12 equal parts, called 

 digits. They are said to have as many digits eclipsed as 12th parts 

 involved in darkness.] 17. Look at fig. 45. and illustrate an eclipse of 

 the moon. 18. At fig. 44. and illustrate an ecUpseof the tun. 



