302 Mr Dunlop's Approwimate Places 



rials have been presented by you to the Royal Society of Lon- 

 don) : and your departure from the colony alone prevented me 

 from pursuing that branch further. 



Finding myself in possession of reflecting telescopes, which I 

 considered capable of adding considerably to our knowledge of 

 the nebulae and double stars in that portion of the heavens, I 

 resolved to remain behind to prosecute my favourite pursuits, 

 in collecting materials towards the formation of a catalogue of 

 the nebulae and double stars in that hemisphere, and any other 

 object which might have attracted my attention. 



The nebulae being a primary object with me, I devoted the 

 whole of the favourable weather in the absence of the moon to 

 that department, and the moonlight, in general, was allotted to 

 the observations of double stars ; a portion only of which I have 

 been able to subject to the various measurements necessary for 

 the accurate determinations of their relative distances and posi- 

 tions. 



In the case of the stars marked with an asterisk, their posi- 

 tions, distances, declinations, &c., are the result of micrometrical 

 measurements with the 46-inch achromatic telescope mounted 

 on the equatorial stand which you left with me: the micrometers 

 were constructed by myself, consisting of a parallel line micro- 

 meter, the screws of which I bestowed great pains upon, and 

 which I consider very excellent and uniform ; also a double 

 image micrometer on Amici's principle, which I sometimes used, 

 particularly when the stars were nearly of equal magnitudes (I 

 always found some uncertainty in the measurements, when the 

 stars were of very unequal magnitudes) : the position microme- 

 ter was made by Bancks, and belongs to the telescope. 



In the case of those stars which are not marked with an 

 asterisk, their positions and distances are only estimations while 

 passing through the field of the 9-feet telescope : in the various 

 sweeps, the right ascensions and declinations are also those 

 which were indicated by the same instrument fitted up and de- 

 scribed as a meridian telescope, in my paper on the nebulae of 

 the southern hemisphere. 



I will only extend at length the observations of a few of the 

 principal stars, merely to show the manner in which they have 

 been conducted. 



