268 THE POPULAR SCIENCE MONTHLY, 



Fig. 8 is a part of Rosse's drawing made with the six-foot tele- 

 scope . 



It will be seen that the number of small stars above and west of 

 the trapezium is very small, but a reference to the original drawing 

 would show that the nebula was traced very far away from the central 

 star : we see from these facts that the famous Rosse telescope is sur- 

 passed by several other telescopes in definition^ but its enormous sur- 

 face, when in good condition, is a great light-gatherer, and a faint 

 nebulosity is distinguished in it more easily than in most other instru- 

 ments — Lassell's reflector, for example. 



Bond, however, has surpassed, by the aid of the 15-inch refractor 

 at Cambridge, the work of Lord Rosse's assistants in every way, even 

 in regard to the very points for which the reflector was best fitted. 

 We must, however, attribute this, in no small degree, to the skill and 

 assiduity of Bond himself. 



We have thus traced the history of the nebula of Orion, as devel- 

 oped by the telescope alone, from its discovery to the present time. 

 This has been done only imperfectly, on account of the impossibility 

 of presenting complete engravings of the drawings made by the dif- 

 ferent observers, to whose work reference has been made. Several 

 other astronomers of note have worked on this subject — notably La- 

 mont and Secchi — but the results of their telescopic work are included 

 in the preceding account. 



The necessary conclusions as to the resolvability and change of 

 the nebula have been indicated, as well as the strong probability 

 that the nebula and the stars in the neighborhood are physically con- 

 nected, which inference is mainly drawn from the recession of the 

 nebula spoken of by Herschel. « 



The progress of telescopic research is well shown by the additions 

 made year by year to our knowledge of this beautiful object, and we 

 have no reason to be ashamed of it. The spectroscope has been busy 

 on this nebula, as with others ; but of its work it is not our purpose 

 to speak. The desideratum in the study of these faint objects seems 

 to be the extension of photography to their delineation. Until that 

 is accomplished, we may rest content with such work as Bond and 

 Struve have left us.^ 



^ It is understood that a drawing of the Orion Nebula is soon to be pubUshed, unde 

 the direction of Prof. Winlock, the present Director of Harvard College Observatory 

 This is to be executed by Mr. Trouvelot, to whom we already owe many beautiful draw 

 ings of celestial objects, published under the auspices of the Harvard College Obser 

 vatory. 



