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Article REMARKABLE SOLAR SPOTS. Page 1 of 5 →
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Remarkable Solar Spots.
REMARKABLE SOLAR SPOTS .
( Continual from paiie 203 ) . August 23 rd , and subsequent days , two adjacent oblong spots were perceptible as one to the unaided eye , and which were first seen near the sun ' s eastern edge , on the 19 th , by the telescope . They were easily resolvable into two with an opera glass , ancl appeared about 10 , 000 miles apart . On the 26 th and 27 th they measured in length , from the extremities of the umbra ? 27562 miles and 31000 miles
respectivel—, , , y the breadth of each being about a third less than its length . The nucleus , or black central spot of the smallest one appeared divided into two parts on the 27 th , ancl into three on the 28 th . On the 30 th they were near the western verge , ancl must have disappeared soon after . Various other large groups studded the sun ' s disc at the same time . On the 29 th August one of these had attained a bulk not much inferior to the foregoing . Another , in its vicinity , which on the 25 th measured
25 , 000 miles in its longest diameter , had stretched out by the 30 th into a very long linked group of small spots , forming a narrow string of 40 . 000 miles in extent ; but it was too attenuated to be visible without the telescope , even had it been longer . These sudden changes or transformations are not uncommon . In fact few spots retain the same size or figure for two days together . Sometimes the forces which thus disturb the sun ' s surface explode ,
as it were , all at once , ancl the spots seem to burst into pieces . A curious instance of this is recorded by Dr . Long , in his Astronomy : while he was viewing the image of the sun cast through a telescope upon white paper , he saw one roundish spot , not much less in diameter than our
earth ( 8000 miles ) , break into two , which immediately receded from one another with a prodigious velocity . Ancl the Rev . Dr . Wollaston once saw a spot break in pieces like a piece of ice when thrown upon a frozen pond , —the fragments flying in different directions . I have frequently , remarked them broken up into fragments , within the space of less than twenty-four hours ; and they as quickly vanish altogether from the view . Sir John Lubbock mentions , in the " Philosophical Magazine , " that he had seen spots so large as to be visible to the naked eyeof which
, not a trace could be found a day or two after . As rapidly do they appear to start into existence . The author of the " Solar System" relates that " On a late occasion I beheld two spots , each of them larger than the earth , and containing at least 300 , 000 , 000 of square miles , which were formed near the centre of the solar disc , where no trace of them was seen forty hours before ; such is the amazing rapidity with which these mihty masses are formedancl again rendered invisible to the
g , sight . " It is rarely that a spot has been seen ( luring several rotations of the sun , though this may be owing to the want of observations . Having followed the two large adjacent spots ( which had appeared as one to the natural eye ) pretty closely to the period of their departure , and taken sketches of their appearance that they might be the more certainly recognized again , should they return , I was upon the outlook about fortniht afterancl the afternoon of the 16 th of
a g , on September , at 4 , p . M ., descried a long , diamond-shaped spot , somewhat advanced on the sun ' s eastern limb . It might have come on the day before , but I had not an opportunity of observing it , ancl the state of the atmosphere was unfavourable . It appeared to occupy the same place on the disc as the former two—still no neighbour appeared in companv . From the
Note: This text has been automatically extracted via Optical Character Recognition (OCR) software.
Remarkable Solar Spots.
REMARKABLE SOLAR SPOTS .
( Continual from paiie 203 ) . August 23 rd , and subsequent days , two adjacent oblong spots were perceptible as one to the unaided eye , and which were first seen near the sun ' s eastern edge , on the 19 th , by the telescope . They were easily resolvable into two with an opera glass , ancl appeared about 10 , 000 miles apart . On the 26 th and 27 th they measured in length , from the extremities of the umbra ? 27562 miles and 31000 miles
respectivel—, , , y the breadth of each being about a third less than its length . The nucleus , or black central spot of the smallest one appeared divided into two parts on the 27 th , ancl into three on the 28 th . On the 30 th they were near the western verge , ancl must have disappeared soon after . Various other large groups studded the sun ' s disc at the same time . On the 29 th August one of these had attained a bulk not much inferior to the foregoing . Another , in its vicinity , which on the 25 th measured
25 , 000 miles in its longest diameter , had stretched out by the 30 th into a very long linked group of small spots , forming a narrow string of 40 . 000 miles in extent ; but it was too attenuated to be visible without the telescope , even had it been longer . These sudden changes or transformations are not uncommon . In fact few spots retain the same size or figure for two days together . Sometimes the forces which thus disturb the sun ' s surface explode ,
as it were , all at once , ancl the spots seem to burst into pieces . A curious instance of this is recorded by Dr . Long , in his Astronomy : while he was viewing the image of the sun cast through a telescope upon white paper , he saw one roundish spot , not much less in diameter than our
earth ( 8000 miles ) , break into two , which immediately receded from one another with a prodigious velocity . Ancl the Rev . Dr . Wollaston once saw a spot break in pieces like a piece of ice when thrown upon a frozen pond , —the fragments flying in different directions . I have frequently , remarked them broken up into fragments , within the space of less than twenty-four hours ; and they as quickly vanish altogether from the view . Sir John Lubbock mentions , in the " Philosophical Magazine , " that he had seen spots so large as to be visible to the naked eyeof which
, not a trace could be found a day or two after . As rapidly do they appear to start into existence . The author of the " Solar System" relates that " On a late occasion I beheld two spots , each of them larger than the earth , and containing at least 300 , 000 , 000 of square miles , which were formed near the centre of the solar disc , where no trace of them was seen forty hours before ; such is the amazing rapidity with which these mihty masses are formedancl again rendered invisible to the
g , sight . " It is rarely that a spot has been seen ( luring several rotations of the sun , though this may be owing to the want of observations . Having followed the two large adjacent spots ( which had appeared as one to the natural eye ) pretty closely to the period of their departure , and taken sketches of their appearance that they might be the more certainly recognized again , should they return , I was upon the outlook about fortniht afterancl the afternoon of the 16 th of
a g , on September , at 4 , p . M ., descried a long , diamond-shaped spot , somewhat advanced on the sun ' s eastern limb . It might have come on the day before , but I had not an opportunity of observing it , ancl the state of the atmosphere was unfavourable . It appeared to occupy the same place on the disc as the former two—still no neighbour appeared in companv . From the