72 CORRESPONDENCE ON ASTRONOMICAL ANNOUNCEMENTS. 



Besides, by giving the B. A. to the nearest tenth of a minute of time 

 and the declination to the nearest minute the observation is available, in 

 the case of a comet for combination to find an appr<jKimate orbit. This 

 form, too, gives the dispatches a permanent value. 



I give the following partly in confirmation of what I think the best 

 features of the proposed systems and partly as suggestions that may 

 probably be of use. 



The greatest clearness seems to be obtained by giving numbers as 

 spoken thus : "12" should be " twelve" and not '-one two" 



I would suggest that the day of the month counted astronomically 

 be absolutely distinguished from the rest of the message by giving it 

 the ordinal form. Thus "October 12 " would be "twelfth October." 



For a like reason the motion in declination might be given as " north- 

 ward" or " southward." If the length of a telegram is estimated by the 

 number of words in it and not by their length, it would seem desirable 

 to exi:)ress " magnitude " in full and not by " mag," which a telegraph 

 clerk would probably coufound with "may "or May." 



Again, if "nought" is objected to why not use "cyj)her" as being in 

 more frequent use than "zero." If the daily motion in B. A. and Bed. 

 is not given, would it not be better to use the words " preceding" and 

 "following" or their symbols "p" and "f," in place of "west" and 

 " east," which latter in practice refer to the horizon and not to the equa- 

 tor. Thus " uf " would represent " northeast." But the daily motions 

 in B. A. and Decl. admit of greater precision. 



A complete message would thus contain the word " comet" or "planet," 

 the discoverer's name, the day (expressed as above) and month, the 

 hour in local mean time and the place. The right- ascension to the 

 nearest tenth of a minute of time, the declination to the nearest minute 

 preceded by the word "north" or "south." Kext, the daily motion in 

 M. A. also to the tenth of a minute of time with the sign "plus" or 

 *' minus " then the daily motion in minutes of arc " northward " or " south- 

 ward," and lastly, the magnitude or any other j)articulars likely to aid 

 the search. 



Thus: 



" Comet Swift twenty-fifth October seventeen Rochester twenty-one 

 fifty-niue cypher north fifty-one twenty-five minus twenty-one two 

 northward fifty-seven magnitude ten." 



"Would mean — 



" Comet discovered by Swift on October 25th at 17'' Rochester mean 

 time in right ascension 21^' SO'^.O and declination + 51^ 25'. Daily 

 motion — 21™.2 and -f 57'. As bright as a star of the tenth magnitude." 



This form of message, although slightly longer than others that have 



dispatch when so transformed, is shown in the example given in the "Proposed Mode 

 of Trausraittiug, &c." where the comet Swift (presumahly discovered at Rochester) 

 must either have been found at 2 p. m. or the longitude have been applied with the 

 \rrong sign. 



