I907 ] PERTAINING TO WORK WITH A PORTRAIT LENS. 419 



these pictures. There are a few of the more prominent nebulae 

 such as the celebrated ones of Orion and Andromeda, which have 

 been drawn by many observers. There is a strange want of resem- 

 blance among these pictures, and what is worse still there is often 

 but little resemblance to the object itself. There was always the 

 possible excuse that the object had actually changed its appearance 

 in the sky. Photography, however, in the past twenty years has 

 shown that such appreciable changes have not really occurred, 

 though they must occur in the course of time. 



The best illustration of this v/ant of harmony in different deline- 

 ations of the same astronomical subject is shown in the large num- 

 ber of drawings of the solar corona made by numerous observers 

 at the total eclipse of the sun in 1878 which were collected and pub- 

 lished by the United States government. No two of the forty odd 

 drawings closely resembled each other and few of them looked at 

 all like the indifferent photographs obtained at the time. Indeed 

 these drawings and other similar ones led an eminent astronomer 

 four years later to declare that the corona was not a real phenome- 

 non belonging to the sun, but that it was partly a diffraction effect 

 and partly in the eye of the observer, so that each observer, as it 

 were, saw a different phenomenon — an idea that no one would think 

 of holding today when photography has long since clearly demon- 

 strated the solar origin of the corona. 



The real cause of these various discrepancies lay mainly in the 

 want of artistic skill in the observer, who saw the things all right 

 but was unable to draw them correctly, especially was this so in 

 the case of an eclipse of the sun, where the excitement of the mo- 

 ment was enough to unnerve most observers. 



Perhaps the greatest sufferer from this want of pictorial skill 

 was the occasional comet. These bodies are really subject to re- 

 markable and rapid changes and hence a misrepresentation was all 

 the more unfortunate. In the case of the nebulae one could simply 

 throw out the poor representations as being due to lack of skill. 

 In the case of the comet no one can tell whether the want of agree- 

 ment in the various drawings was not due to actual changes in the 

 comet itself. Happily today, the lack of artistic skill in the indi- 

 vidual plays almost no part in astronomical work. The photo- 



