378 



PROFESSOR C. PIAZZl SMYTH ON THE 



A simple inspection of the first of the two previous tables may be considered 

 to show, that in magnitude or brightness, an Elchies observation is not likely to 

 be in error more than 1 magnitude on the " Cycle," which follows very nearl}*^ 

 the Herschelian scale ; and in colour, though the estimation was rude, and based 

 entirely on my own independent ideas of colours, yet the Elchies difference from 

 the same standard authority is always comprised within some small variety of one 

 and the same tint, indicating, therefore, the non-existence of chromatic error or 

 equation, personal, instrumental, or geographical, to any large or sensible amount. 



Similarly the second table may be held as exhibiting, that there are hardly 

 any errors of a constant order worth noticing, on either position angles or dis- 

 tances,* as observed at Elchies, while the occasional errors, + and — , are con- 

 fined within a degree for " positions," and a second for " distances," over cases 

 varying in al)Solute distance from 4" to 35". 



These limits of occasional possible error, though they include some cosmical 

 uncertainties in the progress of the stars themselves, may appear rather large 

 when compared with the many decimal places adopted by some few single 

 observers in recording their observ^ations ; but will appear more moderate when 

 we come presently to compare the results of many such first-rate observers inter 

 se ; and will even in the end be found very small, compared to the important 

 natural changes which have undoubtedly been undergone by some of the stars 

 since the last previous observations that have come to my knowledge. 



A. — 6. Stao's observed. 



The following table contains a condensed list of the stars or star-groups 

 observed at Elchies, and arranged in order of Right Ascension : — 





Approx. E. As- 



Approximate De- 





Appros. E. As- 



Approximate De- 



Name. 



cension for 



clination for 1862. 



Name. 



cension for 



clination for 1862, 





1862, Jan. 1. 



Jan. 1. 





1862, Jan. 1. 



Jan. 1. 





h. m. s 







h. m. s. 





35 Piscium, 



7 52 



-f 6 3 14 



55 Serpentis, . 



18 14 11 



- 2 55 35 



65 Piscium, 



42 28 



+ 26 57 31 



a LyrtE, 



18 32 14 



+ 38 39 8 



•v]^' Piscium, 



58 17 



+ 20 44 1 



28 Aquilse, . . 



19 13 14 



+ 12 7 22 



^ Piscium, 



1 6 37 



+ 6 50 44 



b AquiliB, . 



19 18 31 



+ 2 50 25 



y Arietis, . 



1 45 58 



+ 18 37 6 



128 Anseris, 



19 20 26 



+ 19 37 12 



X Arietis, . . 



1 50 15 



+ 22 55 20 



^ Cygni, . . 



19 25 9 



+ 27 40 20 



222 Arietis, . . 



1 51 56 



+ 20 23 14 



^ Sagittse, . . 



19 42 52 



+ 18 47 57 



a Piscium, 



1 54 54 



+ 2 5 45 



a Aquilse, . 



19 44 2 



+ 8 30 5 



y Andromedae, 



1 55 25 



+ 41 40 3 



y Delphini, 



20 40 17 



+ 15 37 54 



32 Eridani, 



3 47 24 



- 3 21 52 



452 Cygni, , . 



20 57 4 



+ 38 58 



a Herculis, 



17 8 21 



+ 14 32 51 



1 Pegasi, . . 



21 15 43 



+ 19 12 56 



1 Herculis, 



17 18 56 



+ 37 16 35 



3 Pegasi, . . 



21 30 51 



+ 602 



95 Herculis, 



17 55 38 



+ 21 35 55 



312 Pegasi, . . 



21 45 6 



+ 19 10 53 



70 Opliiuchi, . 



17 58 28 



+ 2 32 32 



2 2841, . . 



21 47 46 



+ 19 2 53 



* Tlie reading of the equator on the position circle of the Elchies micrometer was obtained 

 every observing night, in the usual manner, by equatorial stars being made to " thread " along a 



