for the year 1876. xv 



depths of the universe. At the Paris observatory a large 

 Newtonian reflector (almost of exactly similar dimensions to 

 our Cassegrainian) has been lately completed, and is now at 

 work ; at Washington the great refractor of 26 inches aperture 

 and 31 feet focal length is actively employed, and in some 

 trials on nebular observation has proved itself no insig- 

 nificant rival to the large apertures of our and the other 

 three large reflectors ; and further, the maker of the Mel- 

 bourne telescope is now engaged in the construction of 

 another enormous refractor for the Vienna Observatory, 

 which is to be 27 inches aperture and about 33 feet focal 

 length. Now that it is likely there will be more busy eyes 

 and large telescopes occupied on the fainter celestial objects, 

 to the observation of which our reflector has been principally 

 devoted, it becomes all the more necessary that what has 

 already been accomplished here should become known. At 

 present very little of the results of the work of the great 

 telescope has been published. I am now, however, in hopes 

 that this will soon be done, as a method of doing it has been 

 decided upon, and the only cause of delay now is the want 

 of means. This, I have no reasonable doubt, will shortly be 

 forthcoming, when a good account will be given of how this 

 magnificent instrument bas been employed since its erection. 

 The final results of the observations of the transit of Yenus 

 have not yet been obtained; the laborious calculations 

 involved will probably delay it for some time longer. It is 

 believed, however, from approximate results already arrived 

 at, that the sun's distance, from these observations, will be 

 found to be somewhere between the distance obtained by 

 the transit of Venus in 1769 (corrected by Stone), and the 

 distance obtained by the parallax of Mars in 1862 ; that is, 

 somewhere between 91,580,000 and 91,240,000 miles. The 

 number of the planetoids (the smaU planets which occupy 

 the gap between the orbits of Mars and Jupiter) already 

 discovered is 161. Most of these bodies are so minute that 



