 The average life of a sun.spot may be taken as two or three months ; the longest yet on record is that of a spot observed in 1840 and 1841, which lasted eighteen months. There are cases, however, where the disappearance of a spot is very soon followed...  The Sun - Page 198by Charles Greeley Abbot - 1911 - 447 pagesFull view - About this book
 | Charles Augustus Young - 1881 - 338 pages
...these short.lived objects are seen but once, not lasting through even a single revolution of the sun. The average life of a sun.spot may be taken as two...a day or two, and sometimes only for a few hours. The spots usually appear not singly, but in groups — at least, isolated spots of any size are less... | |
 | Joseph Anthony Gillet - 1882 - 496 pages
...78. Duration of Sun-Spots. — The average life of a sun-spot is two or three months : the longest on record is that of a spot observed in 1840 and 1841,...repeated. While some spots are thus long-lived, others endure only a day or two, and sometimes only a few hours. 179. Groups of Spots. — The spots usually... | |
 | George Henry Lepper - 1917 - 388 pages
...happens, the parts usually seem to repel each other and fly asunder with great velocity — great, that is, if reckoned in miles per hour, though, of...a day or two, and sometimes only for a few hours. As to the causes of sun-spots Doctor Abbot says (The Sun, p. 188) : The causes which produce sun-spots,... | |
 | George Henry Lepper - 1919 - 424 pages
...happens, the parts usually seem to repel each other and fly asunder with great velocity — great, that is, if reckoned in miles per hour, though, of...a day or two, and sometimes only for a few hours. As to the causes of sun-spots Doctor Abbot says (The Sun, p. 188) : The causes which produce sun-spots,... | |
| |
